The first satellite ____telephone signals was called Early Bird.
| A．was used to send | B．used to be sent |
| C．was used to sending | D．used to send |
Our teachers often encourage us that every minute we spend on studying will finally _______ in the near future.
| A．run out | B．go off | C．come out | D．pay off |
Fever _______ sickness. You should see a doctor at once.
| A．explains | B．informs |
| C．introduces | D．indicates |
Not all the patents________ have been recognized.
| A．to be examined | B．being examined |
| C．examined | D．having been examined |
Unless______, this law will make life difficult for farmers.
| A．changed | B．changing |
| C．being changed | D．is changing |
This year many factories raised the prices of clothes to _____ the higher cost to customers.
| A．pass by | B．pass on |
| C．pass for | D．pass through |