6. --Kitty, how was your weekend?
--I had a great time. I went skiing with my friends.
--Wow! ________.
| A．How interesting you are! | B．Cheers! |
| C．Sounds really cool! | D．I'll go there, too. |
Last term our maths teacher set so difficult an examination problem _____ none of us worked out.
| A．that | B．as | C．so that | D．which |
How pleased the detective was _____ what his customer told him!
| A．hearing | B．heard | C．to hearing | D．to hear |
Mrs. Brown was much disappointed to see the washing machine she had _____ went wrong again.
| A．it repaired | B．to be repaired | C．to repair | D．repaired |
-Has Tommy finished his homework yet?
-I have no idea; he ____ it this morning.
| A．was doing | B．had been doing | C．has done | D．did |
-If you have time tonight，I’d like to invite you to a ball.
-That’s very nice of you，but are you ____?
| A．free | B．careful | C．serious | D．true |