The evening concerts 23 different locations during the 10-day Festival.
答案：(A) are held at
【句型】be held at + 地點，固定搭配，表示「（活動）在……舉辦」，符合演唱會在不同地點舉行的語意。happen to（碰巧）、are taken in（被欺騙／被收留）、participate in（參與）都不符合這裡「舉辦於」的語意。
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concerts 是「音樂會」，音樂會會「發生」，所以 happen to 讀起來好像可以；也有人看到 participate in（參與）覺得音樂會在不同地點「參與」，勉強說得通。這兩個都是把主詞讀錯造成的——音樂會不是動作的執行者，是被安排、被辦出來的那一方。
先確認主詞與空格的關係：主詞是 The evening concerts（晚間音樂會），它自己不會去做什麼，只能被人辦出來，所以這一格要的是被動。四個選項裡 happen to 與 participate in 都是主動，先出局。剩下 are held at 與 are taken in 兩個被動的，再看介系詞與語意：後面接的是 different locations（不同的地點），要的是「在某個地點舉行」，英文的制式說法是 be held at ＋ 地點。國中學過的 The meeting will be held at the school hall.（會議將在學校禮堂舉行）就是這個句型。順便把主動與被動這一組講清楚：同一件事用主動講是 take place（The concert took place at the stadium. 演唱會在體育場舉行），用被動講才是 be held（The concert was held at the stadium.），兩個都對，但不能混成 be taken place 那種寫法。
happen to 後面接的是人（Something strange happened to me yesterday. 我昨天碰上一件怪事），接地點不成話；participate in（參與）的主詞必須是人或團體，音樂會自己不會去參與什麼；are taken in 的 take in 是「收留」或「欺騙」（Don’t be taken in by his promises. 別被他的承諾騙了），語意完全不對。三個選項不是主動被動錯，就是主詞挑錯。
be held at ＋ 地點（在……舉行）、take place（舉行、發生，主動用法）、happen to somebody（發生在某人身上）、participate in（參與）、be taken in by（被……欺騙）、location（地點）
Jazz is not only an American art form but also an international phenomenon. The New Orleans Jazz and Heritage Festival, also called Jazz Fest, is a 10-day cultural feast 21 thousands of musicians, cooks, and craftspeople welcome 500,000 visitors each year.
The main events include unforgettable music on 12 stages, delicious Louisiana cuisine in two large food areas, and crafts artisans from the region and 22 the world purchasing and selling their works. The evening concerts 23 different locations during the 10-day Festival.
The Festival 24 the indigenous music and culture of New Orleans and Louisiana, so the music encompasses every style associated with the 25 and the state: blues, R&B, gospel, Cajun, Afro-Caribbean, folk, Latin, rock, rap, country, bluegrass and everything in between. And of course there is lots of jazz, both contemporary and traditional.