－ Can you help me clean the room?－ OK I have to wash the clothes first.A. soB. butC. bec

问题补充：

－ Can you help me clean the room?

－ OK, I have to wash the clothes first.

A. so

B. but

C. because

D. as

答案：

A. so

(答案→)B. but

C. because

D. as

解析：回答语前句表示答应，后句又说必须首选要洗衣服，表示的是转折，用连词but，故本题选B。