--Sorry, I overslept. I forgot to set the alarm.
--Your clock ________. Perhaps you should buy a new one.
| A．never worked | B．never works |
| C．had never worked | D．is never working |
I _______ Anna since three years ago．（ ）
A．knewB．knowC．have known
If I go to the movie， I _______ my homework on time．（ ）
A．didn't finishB．don't finish
C．won't finish
I like Chinese， _______ I don't like math， because it's not easy to learn it well．（ ）
A．andB．butC．or
I think it's impolite _______ others waiting．（ ）
A．to keepB．keepingC．keep
I cleaned my room yesterday． It _______ a little difficult．（ ）
A．isB．wasC．will be