1. The coffee is very cold; it needs ____.

　　A. hot B. to heating C. to be heated D. to be hotted

　　2. The professor was knowledgeable and humorous and ___ with enthusiasm.

　　A. was always listened B. was always listened to

　　C. always was listened D. always listen to

　　3. He returned at midnight and found his house _____.

　　A. had broken into B. was broken in

　　C. to be broken D. had been broken into

　　4. They ___ how to operate the machines.

　　A. are being shown B. are being showing

　　C. were to be shown D. have been showing

　　5. The principal of the university had his secretaries ___ a conference.

　　A. arrange B. to arrange C. arranging D. arranged

　　答案及解析：

　　1. [C]

　　解析：needs 后面应跟heating 或 to be heated。

　　2. [B]

　　解析：listen 是不及物动词，没有被动语态，listen to 可看作及物动词，有被动语态。

　　3. [D]

　　解析：主句是过去时，从句中动作发生在主句动作之前，并且是被动，所以选D。

　　4. [A]

　　解析：被动语态的现在进行时。

　　5. [A]

　　解析：have 后面接不带to 的不定式作宾语补足语。