Since… 和完成時態連用。

　　e.g. Since he was born， he has been troubled by frequent colds.

　　考點：考察常見介詞的習慣用法。

　　7. D. 分析：借助句子中的相關詞語（bomber planes）含義直接判斷答案。

　　補充：

　　On： 表示…的狀態或過程，表…的意圖

　　on leave/休假； on fire/著火； on the way/在途中

　　travel on business商務旅行

　　考點：考察常見動詞短語。

　　take up v.拿起， 開始從事， 占據

　　take after v.象， 學樣

　　take.。as.。：把。。看作。。

　　Later that day， all communications with Flight 1 9 were lost．They just disappeared without a trace．

　　The next morning，242 planes and 19 ships took part in the largest air-sea search in history． But they found nothing. 8． A)for B) about C) on D) from

　　Some people blame the disappearances__8__supernatural forces．

　　8． C．分析：借助搭配結構 (blame the disappearance.。 supernatural force)判斷C是答案。

　　考點：考察常見動詞短語。

　　blame 。。(on， upon)。。 把。。。歸咎于。。

　　e.g. Dont blame it on him， but on me.別怪他， 該怪我。

　　Blame.。for.。指責。。造成了。。

　　e.g. They blamed the secretary for the delay of the plan.他們怪罪秘書造成計劃延誤。

　　9．A)missing B) missed C) miss D) having missed