—Have a break,Amy．You _____________ playing the piano all the morning．
—OK，Mom．I will stop after this piece．
| A．are practicing | B．have practiced |
| C．have been practicing | D．practiced |
If I had worked harder at school, I in a comfortable office now．
| A．would sit | B．would have sat | C．would be sitting | D．were sitting |
twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city．
| A．Examining | B．Examined | C．Being examined | D．Having been examined |
, he wanted to buy his son a cheap toy for his birthday．
| A．As he is short of money | B．He was short of money |
| C．Short of money as he was | D．As was he short of money |
They considered a computer, which was considereda great help in their work．
| A．to buy; to be | B．buying; being | C．to buy; being | D．buying; to be |
If we can our present difficulties, then everything should be all right?
| A．come across | B．get over |
| C．come over | D．get off |