Small sailboats can easily turn over in the water ______ they are not managed carefully.
| A．though | B．before | C．until | D．if |
The temperature has risen to more than 20 degrees centigrade. It is quite hot _______January in Zhejiang.
| A．for | B．in | C．as | D．like |
--- Jack fell off the ladder yesterday, but he is all right now.
---What a lucky dog! He _______ himself badly.
| A．could injure | B．must have injured |
| C．should injure | D．might have injured |
---Tell us, Mark, what is the cause of the American Civil War?
---Well, is it _______the black slaves wanted freedom?
| A．how | B．why |
| C．because | D．when |
--- I can’t carry the luggage. It’s so heavy.
--- Why not have someone strong enough_______ you a hand then?
| A．give | B．to give |
| C．giving | D．to have given |
Although she brushed the old pot_______, she could not make it completely clean, which made her very upset.
| A．roughly | B．thoroughly |
| C．instantly | D．occasionally |