They showed me a medicine that was scientifically ______ from human hair and used in helping their growth.
| A．learned | B．chosen | C．prepared | D．separated |
-The rescue team made every __________ to find the missing mountain climber.
| A．force | B．energy | C．effort | D．possibility |
- 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 |