A. careful as B. more carefully than C. as careful as D. carefully than

A. Where their tent is.B. Where to set up the tent.

C. How to recognize different trees.

A. Help the man’s wife find a doctor.B. Call an ambulance.

C. Take the man to the hospital.

A. where I put B. where did I put

C. where will I put D. where I will put

A. Watching a film.B. Reading a novel.C. Eating a meal in the cafeteria.

A. has begun B. has been on C. had begun D. had been on

--- She wondered ______ we could complete the experiment.

A. when was itB. it was when that

C. it was whenD. when it was that

A. anything bad B. bad something C. something bad D. everything bad

--- Don’t mention it.

A. will have beenB. would have been

C. must beD. could be

A. Having exposedB. Being exposed

C. To exposeD. Exposed