---May I smoke here?
---If you _______, choose a seat in the smoking section.
| A．should | B．could | C．may | D．must |
At minus 130℃, a living cell can be __________ for a thousand years.
| A．spared |
| B．protected |
| C．preserved |
| D．developed |
—Mom, Tom asked me to play football with him.
Shall I go out now?
—__________. Be careful and don't play in the street.
| A．Yes, you will |
| B．With pleasure |
| C．Of course not |
| D．Sure |
We must __________ him to be innocent until he is proved guilty.
| A．assume |
| B．accomplish |
| C．attain |
| D．assemble |
__________ he knew that his children would not find their way back this time.
| A．Somehow |
| B．Somewhat |
| C．However |
| D．Anyway |
Being poor, they had to build a__________ shelter out of tree trunks.
| A．common |
| B．normal |
| C．primitive |
| D．formal |