__________ of furniture have been tested to guarantee good quality.
| A．A great deal of | B．A large number of | C．Large quantities | D．A good many |
Mary _______ her mother with the housework, but she didn’t.
| A．must have helped | B．ought to have helped |
| C．must help | D．should help |
The local government announced that only when the fire was under control ________ to return to their homes.
| A．the residents would be allowed | B．had the residents been allowed |
| C．would the residents be allowed | D．the residents had been allowed |
He left home without saying a word, and _______ worries many people and is to be found out.
| A．where he has gone | B．where did he go |
| C．which place has he gone | D．where has he gone |
He came all the way to China for learning it better _______ for making money.
| A．other than | B．more than | C．better than | D．rather than |
Evidence gained from observation and experiment is often used to _______ a scientific theory.
| A．concern | B．confirm | C．consult | D．combine |