．_________life began on the earth is one of the biggest puzzles to scientists.
| A．How | B．What | C．Where | D．That |
—My teacher says she’s cancelling the class play. I just can’t understand.
—______.You were looking forward to it.
| A．It doesn’t matter | B．It’s very unwise of her |
| C．Don’t worry about it | D．You must be disappointed |
I’m very glad to see that your vocabulary is gradually ________.
| A．building up | B．turning up | C．coming up | D．waking up |
More than twenty years____________since he came to teach in this school, and every student and every parent_____him.
| A．have passed,like | B．has passed,likes |
| C．have passed,likes | D．has passed,like |
________ thousands of Chinese students，Chuck has vast experience in the Chinese class.
| A．Having taught | B．Taught |
| C．Teaching | D．To have taught |
We do not have enough money.________，we cannot afford to buy the new car.
| A．However | B．Anyway | C．Therefore | D．Though |