Exploring _____space is exciting, yet dangerous.
There is _____need for both robots and humans for space exploration.
| A．the; a | B．a; a | C．/; a | D．/; the |
- I'm sorry. I ____________you _______ to me.
| A．don’t know; are speaking |
| B．don't know; were speaking |
| C．didn't know; were speaking |
| D．didn't know; are speaking |
--Hi, Tracy, you look tired.
--I am tired. I________ the living-room all day.
| A．painted | B．have been painting |
| C．had painted | D．have painted |
- The reason_________ he didn't come was _________ he had to take care of his sick mother.
| A．why; that | B．why; which |
| C．which; why | D．that; for |
-"Please __________why you're so late," said his girlfriend.
| A．excuse | B．explain | C．apologize | D．tell |
---- Is there anyone in your class ____ the name of Mary?
----____.
| A．whose; No | B．her; None | C．by; No one | D．called; Nobody |