----Is Jack in the next room ?

----Well, it’s hard to say. But I heard him ______ loudly when I passed by just now.

A. speak B. to speak C. spoken D. speaking

D 【解析】 句意：——汤姆在隔壁房间吗？——嗯，很难说。但是当我刚才经过的时候，听到他正在大声讲话。hear sb. doing sth. 听见某人正在做某事，现在分词短语作宾语补足语，hear sb. do sth.听见某人做过某事，根据when I passed by just now（刚才我经过时）可知，是强调动作正在进行，故答案选D。

The student corrected his paper carefully, ____the professor’s suggestions.

A. follow B. following C. followed D. being followed

B 【解析】句意: 根据教授的建议，学生认真地修改了论文。A. follow动词，跟随、遵循；B. following 现在分词或动名词，跟随、遵循；C. followed过去式或过去分词，跟随、遵循；D. being followed现在分词的被动结构。根据句意可知，本句为现在分词作状语，它的逻辑主语就是句中的主语。故选：B。

When I walked past the park, I saw some old people ________ Chinese Taiji.

A. does B. did C. doing D. are doing

C 【解析】 试题解析：句意：当我经过公园的时候，我看见一些老人在打太极拳。看见某人在做某事用see somebody doing something，所以选C。

I found a letter _________ on the floor when I came into the classroom.

A. lying B. lay C. lie D. lies

A 【解析】 试题句意：当我进教室的时候，我发现地板上有一封信。Find sb doing sth发现某人做某事，所以选A。

He wants to have his TV ________.

A. repairing B. repaired C. to repair D. to be repairing

B 【解析】句意: 他想找人修理他的电视机。A. repairing现在分词或动名词，修理；B. repaired过去式或过去分词，修理；C. to repair不定式，修理；D. to be repairing动词不定式的进行时态。“ have + sth. （宾语）+ 过去分词（宾语补足语）”意为“让 / 叫 / 使 / 请别人做某事”。宾语sth. 后面用过去分词作宾语补足语，说明st...

Seeing their teacher _______ into the classroom, they stopped _______ at once.

A. walk; telling B. entering; to speak C. enter; to tell D. walking; talking

D 【解析】 see sb doing sth看见某人在做某事；stop doing sth停止做某事。

______ the bad news made him cry.

A. Hear B. Heard C. Hearing D. Is hearing

C 【解析】句意: 听到这个坏消息，他哭了起来。A. Hear动词，听到；B. Heard过去式或过去分词，听到；C. Hearing现在分词或动名词，听到；D. Is hearing进行时态的结构。根据句意可知，本句缺少主语，动名词可以作主语。故选：C。

When a man’s heart stops ______ , he dies.

A. to beat B. beating C. beat D. beaten

B 【解析】句意: 当一个人的心脏停止跳动时，他就死了。A. to beat不定式，跳动；B. beating现在分词或动名词，跳动；C. beat动词，跳动；D. beaten过去分词，跳动。stop doing，意为“停止做某事”，表示停止正在做的事情,符合本题语境；stop to do, 意为“停下来做某事”，to do是要做的事情。故选：B。

It goes without _______ that knowledge is important.

A. says B. to say C. saying D. said

C 【解析】句意: 不言而喻，知识是重要的。A. says动词三单、说；B. to say动词不定式，说；C. saying现在分词或动名词，说；D. said过去式或过去分词，说。without介词，没有；后跟名词/代词/动名词。 故选：C。

We'd better ________off our mobile phones. The meeting will start in a minute.

A. to turn B. turning C. turn D. turned

C 【解析】句意: 我们最好关掉手机。会议马上就要开始了。turn off关掉。根据“had better+动词原形”，最好做某事，所以本题使用动词原形turn。故选：C。