The exhibit, opened in December 2008, 20 scheduled to run for about three years.
答案：(A) is
opened in December 2008 是插入的分詞片語，用來修飾主詞 The exhibit，句子仍缺一個限定動詞，故填 is，構成 be scheduled to（預定）；being 與 having 都是分詞，has 則會使語態變成主動而不合。
句子中間插了 opened in December 2008，你看到 opened 就當它是主要動詞，覺得句子已經完整，於是不知道空格要填什麼。這個分詞片語只是修飾主詞，等於 which was opened in December 2008。
讀英文句子，先抓兩樣東西：誰、怎麼了——主詞與動詞。這兩樣定了，其餘都是掛在上面的修飾語。先把句子切開看：[The exhibit], opened in December 2008, ___ scheduled to run for about three years. 方括號裡是主詞，緊接著兩個逗號夾住一段修飾語；把它遮掉，剩下 [The exhibit] ___ scheduled…，動詞該站的位置立刻現形。眼睛先撞到 opened 就把它當成動詞，是這一題最容易出的錯。主詞後面接逗號的句子都可以這樣處理：先確認逗號之間是不是修飾語（分詞片語、同位語、介系詞片語），是就遮掉。骨幹露出來之後，要填的是一個有時態的動詞。scheduled 在這裡是過去分詞——展覽是「被安排」的一方，所以要配 be 動詞構成 be scheduled to V（預定要…）。主詞 The exhibit 單數，全文用現在式敘述現況，因此填 is。這個結構你國中就用過：The boy standing there is my brother.（站在那裡的男孩是我哥哥。）standing there 是修飾語，is 才是主要動詞。本題只多兩件事——修飾語換成過去分詞，是被動；而且用兩個逗號插在主詞與動詞中間，把兩者隔得比較開，更容易看走眼。
being 與 having 都是分詞、沒有時態，當不了主要動詞，填進去整句會變成一個沒有動詞的名詞片語。has 的問題不同：has scheduled 是主動語態，意思變成「展覽安排了某件事」，但展覽是被安排的一方，語態顛倒；要用 has，得寫成 has been scheduled 才通。這個方法在學測 104 年第 18 題也考過同一個概念：These movements, forming an exercise system, ___ one to effortlessly experience the vital life force.——插入語換成現在分詞，遮掉之後要判斷的是主詞單複數（These movements 要配 allow）。學測 108 年第 17 題是第三種：However, many people, either refusing to accept the new date or not having heard about it, ___ to celebrate New Year’s Day on April 1.——插入語是兩個並列的分詞片語，遮掉之後要判斷的是主要動詞的時態（要配 continued）。本題遮掉之後要判斷的是語態。遮住插入語只是第一步，第二步永遠是問：這個主詞跟這個動詞，在數與語態上對得起來嗎？
be scheduled to V（預定要）、be due to V（預計）、be set to V（即將）、run for（持續、上演）、reproduction（複製品）、keep one's hands off（不碰、別動）。
Signs asking visitors to keep their hands off the art are everywhere in the Louvre Museum, Paris. But one special sculpture gallery invites art lovers to allow their hands to 16 the works. The Louvre's Tactile Gallery, targeted at the blind and visually 17, is the only space in the museum where visitors can touch the sculptures, with no guards or alarms to stop them.
Its latest exhibit is a 18 of sculpted lions, snakes, horses and eagles. The 15 animals exhibited are reproductions of famous works found elsewhere in the Louvre. Called "Animals, Symbols of Power," the exhibit 19 animals that were used by kings and emperors throughout history to symbolize the greatness of their reigns.
The exhibit, opened in December 2008, 20 scheduled to run for about three years. During guided tours on the weekends, children can explore the art with blindfolds on.