I know ______ is important to know my own limitations, but _______ is difficult is to help others to know their own limitations.
| A．it, it | B．what, what |
| C．it, what | D．what, it |
--- Look at the black clouds. It ______ soon.
--- Sure. If only we ______ out.
| A．is raining; didn’t come |
| B．is to rain; won’t start |
| C．will rain; haven’t started |
| D．is going to rain; hadn’t come |
--- ______ Betty this morning?
--- Not yet, but she is sure to be here before noon.
| A．Have you seen | B．Will you see |
| C．Do you see | D．Did you see? |
. --- Is Tom still smoking?
--- No. By next Saturday he ______ for a whole month without smoking a single cigarette.
| A．will be | B．will have gone |
| C．will have been | D．has been going |
I used to drink a lot of tea but these days I ______ coffee.
| A．prefer | B．preferred |
| C．had preferred | D．am preferring |
The train ______ at the present speed until it reaches the foot of the mountain at about nine o’clock tonight.
| A．went | B．is going | C．goes | D．will be going |