．The children are having a good time, ______ with sand, others with toys．
| A．some of them playing | B．some of them are playing |
| C．some of them | D．who playing |
how to work out the difficult physics problem ,he asked the teacher for help .
| A．Not to know | B．Not knowing | C．Knowing not | D．Not known |
“Mum !” she cried suddenly , tears down her cheeks .
| A．rolling | B．rolled | C．to roll | D．being rolled |
prices , we have to take into consideration the quality of the goods .
| A．While compared | B．Compared | C．Compare | D．When comparing |
you meet with new words when reading English articles , you can guess the meaning first .
| A． Every time | B．First time | C．For the first time | D．At the time |
As it turned out to be a problem of no importance , we so much time looking into it .
| A．needn’t spend | B．didn’t have to spend |
| C．needn’t have spent | D．oughtn’t to spend |