The speaker _____ several other subjects in the course of his talk but mostly kept himself to the main topic.
| A．held on | B．worked out | C．touched on | D．kept out of |
I'm sorry you ______ so long, but it' ll still be some time before Jim gets back．
| A．wait | B．waited | C．had waited | D．have been waiting |
In college, you will discover ______ learning is about, from teacher-taught to self-learner．
| A．which | B．that | C．what | D．where |
Since the end of the war, many of the priceless antiques ______ to their rightful owners．
| A．have returned | B．had returned |
| C．had been returned | D．have been returned |
_______the money shortage, many small companies closed down.
| A．As a result from | B．As a result | C．Resulted in | D．As a result of |
Do you know the thief_______by the police.
| A．has been catching | B．has caught | C．has been caught | D．will caught |