. ___ to nuclear radiation, even for a short time may produce variants（变异体）of genes in human bodies.
| A．Being exposed | B．Having exposed |
| C．Exposed | D．After being exposed |
. The computer games you are addicted to _____ dangerous to students’ bodies and spirits.
| A．be | B．is | C．being | D．are |
. You’re so tired. We should have driven the car _____ .
| A．by turn | B．in turn | C．in turns | D．on turn |
Immediately he was elected monitor, James _____ his duties since.
| A．took up | B．has taken up | C．made up | D．has made up |
. After many years’ hard work, his career really _____ and he became world famous.
| A．took on | B．took off | C．took up | D．took away |
. –Mike, than you for helping me.
--_____.
Which is a wrong one below?
| A．My pleasure | B．With pleasure | C．You’re welcome | D．That’s alright |