About seventy percent of our earth _______ by water.
| A．is covering | B．is covered |
| C．are covered | D．are covering |
— Do you think you can repair the car by yourself?
—______It's not the first time for me.
A. Don't worry B. Hurry up
C. Sorry, I can't d. Not at all
— Do you know why he left so early?
—_______for the English test, I guess.
| A．To study | B．Study | C．Studied | D．Studying |
— I think your father is very busy.
—So he is._______ he still takes a walk with us sometimes.
A. SoB. And 
C. Or d. But
— May I speak to Mr Morgan?
— Sorry. He______on the farm.
| A．works. | B．worked |
| C．is working | D．has worked |
— You like listening to Sally's songs, don't you?
—_______.She has a sweet voice.
| A．Yes. I do | B．Yes, she does |
| C．No, 1 don't | D．No, she doesn't |