________ is now no ________ that global warming is a security threat to us all.
| A．There；doubt |
| B．There；need |
| C．It；doubt |
| D．It；need |
_____ through this book and tell me what you think of it.
| A．Look | B．Looking |
| C．To look | D．Having looked |
_____ me, and then try to copy what I do.
| A．Watch | B．Watching |
| C．To watch | D．Have watching |
_____ the milk and set a good example to the other children.
| A．Drink | B．To drink |
| C．Drinking | D．Having drinking |
_______ to the top of the hill, and you can see the whole of the town.
| A．Get | B．To get |
| C．Getting | D．Having got |
Everyone in our class was working hard and doing what we could _______ a good college.
| A．enter | B．to enter |
| C．entering | D．entered |