diff --git a/lib/router.js b/lib/router.js
index dcb959fb8..488de8eb2 100644
--- a/lib/router.js
+++ b/lib/router.js
@@ -3767,6 +3767,6 @@ router.get('/sciencenet/blog/:type?/:time?/:sort?', require('./routes/sciencenet
 router.get('/dailyart/:language?', require('./routes/dailyart/index'));
 
 // Media Digest
-router.get('/mediadigest/:category?', require('./routes/mediadigest/category'));
+router.get('/mediadigest/:range/:category?', require('./routes/mediadigest/category'));
 
 module.exports = router;
diff --git a/lib/routes/mediadigest/category.js b/lib/routes/mediadigest/category.js
index b42a27f64..757541d4b 100644
--- a/lib/routes/mediadigest/category.js
+++ b/lib/routes/mediadigest/category.js
@@ -1,79 +1,238 @@
 const got = require('@/utils/got');
 const cheerio = require('cheerio');
 
-function getArticle(ctx, line, tasks) {
-    const article = ctx.cache.tryGet(line, async () => {
-        const a_r = await got.get(`https://app3.rthk.hk/mediadigest/${line}`);
-        const $ = cheerio.load(a_r.data);
-        // title
-        const h1 = $('h1.story-title').text();
-        // author
-        const author_list = $('div.story-author');
-        const authors = author_list.map((_index, author) => $(author).text());
-        const author = authors.map((_index, author) => `<b>${author}</b><br>`);
-        const s_author = author.toArray().join('');
-        const author_block = `<blockquote><p>${s_author}</p></blockquote>`;
-        // date
-        const date = $('div.story-calendar').text();
-        // desc
-        const desc = `${$(author_block)}${$('div.story-content').html()}`;
+function getArticle(ctx, list) {
+    // for 每次可爲 rss 値推入 20 篇文章內容
+    for (let start = 0; start < list.length; start += 20) {
+        // 建立一個切片 (20 個文章 URL) 異步獲取文章內容的任務
+        let now = list.slice(start, start+20).forEach((line) => {
+            ctx.cache.tryGet(line, async() => {
+                const a_r = await got.get(`https://app3.rthk.hk/mediadigest/${line}`);
+                const $ = cheerio.load(a_r.data);
+                // title
+                const h1 = $('h1.story-title').text();
+                // author
+                const author_list = $('div.story-author');
+                const authors = author_list.map((_index, author) => $(author).text());
+                const author = authors.map((_index, author) => `<b>${author}</b><br>`);
+                const s_author = author.toArray().join('');
+                const author_block = `<blockquote><p>${s_author}</p></blockquote>`;
+                // date
+                const date = $('div.story-calendar').text();
+                // desc
+                const desc = `${$(author_block)}${$('div.story-content').html()}`;
 
-        return {
-            title: h1,
-            description: desc,
-            pubDate: new Date(`${date}T09:00:00+0800`).toUTCString(),
-            link: line,
-        };
-    });
-    tasks.push(article);
+                return {
+                    title: h1,
+                    description: desc,
+                    pubDate: new Date(`${date}T09:00:00+0800`).toUTCString(),
+                    link: line,
+                };
+            });
+        })
+        // 執行一個切片 (20 個文章 URL) 的任務並將結果資料推至 rss 値
+        rss.push(...(await Promise.all(now)));
+    }
 }
 
-module.exports = async (ctx) => {
+module.exports = async(ctx) => {
+    const range = ctx.params.range || 'latest';
     const category = ctx.params.category || 'all';
-    const tasks = [];
 
-    if (category !== 'all') {
-        const response = await got.get(`https://app3.rthk.hk/mediadigest/category.php?cid=${category}`);
-        const $ = cheerio.load(response.data);
-        const list = $('div.category-line');
-
-        list.map((_index, line) => $(line).find('a').first().attr('href')).each((_index, line) => {
-            getArticle(ctx, line, tasks);
-        });
-    } else {
-        const cids = [1, 2];
-        for (let i = 4; i < 28; ++i) {
-            cids.push(i);
-        }
-        const urls = cids.map((cid) => `https://app3.rthk.hk/mediadigest/category.php?cid=${cid}`);
-        const list_allt = await Promise.all(
-            urls.map(async (url) => {
-                const response = await got.get(url);
-                const $ = cheerio.load(response.data);
-                const list = $('div.category-line').map((_index, line) => $(line).find('a').first().attr('href'));
-                return Promise.resolve(list.toArray());
-            })
-        );
-        const list_all = [...new Set(list_allt.flat())];
-
-        const list_recent_20 = list_all
-            .sort((a, b) => {
-                const aid_a = a.match(/aid=(\d+)/)[1];
-                const aid_b = b.match(/aid=(\d+)/)[1];
-                // reverse
-                return aid_b - aid_a;
-            })
-            .slice(0, 20);
-        list_recent_20.forEach((line) => {
-            getArticle(ctx, line, tasks);
-        });
+    // for range validation
+    var num = /^[0-9]+$/;
+    var current_year = new Date().getFullYear();
+    // placeholder for rss
+    let rss = [];
+    // cid
+    const cids = [1, 2];
+    for (let i = 4; i < 28; ++i) {
+        cids.push(i);
     }
 
-    const rss = await Promise.all(tasks);
+    // latest (50 articles):
+    // if 'all' (latest 50 articles of the site);
+    // else if 'cid' (all articles of a specific category);
+    // else 'error'.
+    if (range === 'latest') {
+        if (category === 'all') {
+            // 獲取全站文章 URL
+            const urls = cids.map((cid) => `https://app3.rthk.hk/mediadigest/category.php?cid=${cid}`);
+            const list_allt = await Promise.all(
+                urls.map(async(url) => {
+                    const response = await got.get(url);
+                    const $ = cheerio.load(response.data);
+                    const list = $('div.category-line').map((_index, line) => $(line).find('a').first().attr('href'));
+                    return Promise.resolve(list.toArray());
+                })
+            );
+            const list_all = [...new Set(list_allt.flat())]; // removed duplicates and flatten 
+            // 時序排列並抽取最新 50 項
+            const list = list_all
+                .sort((a, b) => {
+                    const aid_a = a.match(/aid=(\d+)/)[1];
+                    const aid_b = b.match(/aid=(\d+)/)[1];
+                    // reverse
+                    return aid_b - aid_a;
+                })
+                .slice(0, 50);
+            // getArticle(ctx, list);
+            // for 每次會可爲 rss 値段推入 20 篇文章內容
+            for (let start = 0; start < list.length; start += 20) {
+                // 建立一個切片 (20 個文章 URL) 異步獲取文章內容的任務
+                let now = list.slice(start, start+20).forEach((line) => {
+                    ctx.cache.tryGet(line, async() => {
+                        const a_r = await got.get(`https://app3.rthk.hk/mediadigest/${line}`);
+                        const $ = cheerio.load(a_r.data);
+                        // title
+                        const h1 = $('h1.story-title').text();
+                        // author
+                        const author_list = $('div.story-author');
+                        const authors = author_list.map((_index, author) => $(author).text());
+                        const author = authors.map((_index, author) => `<b>${author}</b><br>`);
+                        const s_author = author.toArray().join('');
+                        const author_block = `<blockquote><p>${s_author}</p></blockquote>`;
+                        // date
+                        const date = $('div.story-calendar').text();
+                        // desc
+                        const desc = `${$(author_block)}${$('div.story-content').html()}`;
+
+                        return {
+                            title: h1,
+                            description: desc,
+                            pubDate: new Date(`${date}T09:00:00+0800`).toUTCString(),
+                            link: line,
+                        };
+                    });
+                })
+                // 執行一個切片 (20 個文章 URL) 的任務並將結果資料推至 rss 値
+                rss.push(...(await Promise.all(now)));
+            }
+        } else if (cids.includes(category)) {
+            // 獲取特定 category 文章目錄
+            const response = await got.get(`https://app3.rthk.hk/mediadigest/category.php?cid=${category}`);
+            const $ = cheerio.load(response.data);
+
+            const list = $('div.category-line').map((_index, line) => $(line).find('a').first().attr('href')).toArray();
+            // getArticle(ctx, list);
+            // for 每次會可爲 rss 値推入 20 篇文章內容
+            for (let start = 0; start < list.length; start += 20) {
+                // 建立一個切片 (20 個文章 URL) 異步獲取文章內容的任務
+                let now = list.slice(start, start+20).forEach((line) => {
+                    ctx.cache.tryGet(line, async() => {
+                        const a_r = await got.get(`https://app3.rthk.hk/mediadigest/${line}`);
+                        const $ = cheerio.load(a_r.data);
+                        // title
+                        const h1 = $('h1.story-title').text();
+                        // author
+                        const author_list = $('div.story-author');
+                        const authors = author_list.map((_index, author) => $(author).text());
+                        const author = authors.map((_index, author) => `<b>${author}</b><br>`);
+                        const s_author = author.toArray().join('');
+                        const author_block = `<blockquote><p>${s_author}</p></blockquote>`;
+                        // date
+                        const date = $('div.story-calendar').text();
+                        // desc
+                        const desc = `${$(author_block)}${$('div.story-content').html()}`;
+
+                        return {
+                            title: h1,
+                            description: desc,
+                            pubDate: new Date(`${date}T09:00:00+0800`).toUTCString(),
+                            link: line,
+                        };
+                    });
+                })
+                // 執行一個切片 (20 個文章 URL) 的任務並將結果資料推至 rss 値
+                rss.push(...(await Promise.all(now)));
+            }
+        } else {
+            rss = ['<p>Invalid <code>:category?</code> input.</p><p>所輸入<code>:category?</code>參數有誤。</p><p>所输入<code>:category?</code>参数有误。</p>'];
+        }
+    }
+    // year (specific year range):
+    // if 'all' (all articles in a specific year range);
+    // else 'error'.
+    else if (range.length === 4 && range !== 0 && num.test(range) && !((range < 1970) || (range > current_year))) {
+        if (category === 'all') {
+            // 獲取全站文章 URL
+            const urls = cids.map((cid) => `https://app3.rthk.hk/mediadigest/category.php?cid=${cid}`);
+            const list_all = await Promise.all(
+                // 每個任務是篩選出一個文章目錄裏需要抓取的文章 URL，以供後續「獲取全文」
+                urls.map(async(url) => {
+                    const response = await got.get(url);
+                    const $ = cheerio.load(response.data);
+                    // 對應文章 URL 與年份
+                    // Ref: https://cythilya.github.io/2016/03/13/jquery-map-grep/
+                    const list_t = $('div.category-line').map((_index, line) => $(line).find('a').first().attr('href')).toArray();
+                    const year = $('div.category-line div.pull-right').map((_index, date) => new Date($(date).text()).getFullYear()).toArray();
+                    // 將 list_t 與 year 一一對應，組成 JSON
+                    // Ref: https://stackoverflow.com/questions/30124979/merge-two-arrays-into-one-javascript-object
+                    function article(year, url) {
+                        this.year = year;
+                        this.url = url;
+                    }
+                    var dlist = [];
+                    for (var i = 0; i < list_t.length; i++) {
+                        dlist.push(new article(year[i], list_t[i]));
+                    }
+                    // 篩出 list (需要抓取的文章 URL 並組成數列)
+                    list = dlist.filter((w) => w.year === range).map((article) => (article.url));
+                    return Promise.resolve(list);
+                })
+            );
+            const list = [...new Set(list_all.flat())]; // removed duplicates and flatten
+            // getArticle(ctx, list);
+            // for 每次會可爲 rss 値段推入 20 篇文章內容
+            for (let start = 0; start < list.length; start += 20) {
+                // 建立一個切片 (20 個文章 URL) 異步獲取文章內容的任務
+                let now = list.slice(start, start+20).forEach((line) => {
+                    ctx.cache.tryGet(line, async() => {
+                        const a_r = await got.get(`https://app3.rthk.hk/mediadigest/${line}`);
+                        const $ = cheerio.load(a_r.data);
+                        // title
+                        const h1 = $('h1.story-title').text();
+                        // author
+                        const author_list = $('div.story-author');
+                        const authors = author_list.map((_index, author) => $(author).text());
+                        const author = authors.map((_index, author) => `<b>${author}</b><br>`);
+                        const s_author = author.toArray().join('');
+                        const author_block = `<blockquote><p>${s_author}</p></blockquote>`;
+                        // date
+                        const date = $('div.story-calendar').text();
+                        // desc
+                        const desc = `${$(author_block)}${$('div.story-content').html()}`;
+
+                        return {
+                            title: h1,
+                            description: desc,
+                            pubDate: new Date(`${date}T09:00:00+0800`).toUTCString(),
+                            link: line,
+                        };
+                    });
+                })
+                // 執行一個切片 (20 個文章 URL) 的任務並將結果資料推至 rss 値
+                rss.push(...(await Promise.all(now)));
+            }
+        } else  {
+            rss = ['<p>Please do not filter with both year and category.</p><p>請不要同時限定年份及分類。</p><p>请不要同时限定年份及分类。</p>'];
+        }
+    } else {
+        rss = ['<p>Invalid <code>:range</code> input.</p><p>所輸入<code>:range</code>參數有誤。</p><p>所输入<code>:range</code>参数有误。</p>'];
+    }
+
+/*     // 分批次处理 tasks，每次拉取 20 个
+    if (rss.length === 0) {
+        for (let start = 0; start < tasks.length; start += 20) {
+            let now = task.slice(start, start+20);
+            rss.push(...(await Promise.all(now)));
+        }
+    }
+ */
 
     ctx.state.data = {
         title: '傳媒透視',
         link: 'https://app3.rthk.hk/mediadigest/index.php',
         item: rss,
     };
-};
+};
\ No newline at end of file