If human beings had been a bit less greedy and cruel, more birds and animals dying out.
| A．ought to avoid | B．could have been avoided |
| C．should have avoided | D．might have avoided |
We had to _________ the engine piece by piece for transport.
| A．take up | B．take out | C．take off | D．take apart |
The little boy was in danger. The doctors and nurses are doing him.
| A．what they can do help | B．everything they can help |
| C．what they can to help | D．all what to help |
_______ the end of last term, we had learned 3,000 English words.
| A．At | B．By | C．To | D．On |
Through the satellites, we can send and _______ messages.
| A．pick up | B．pick out | C．take up | D．take in |