— swim in the river? — oh, no. Our teacher told us here. It’s dangerous. A. Why don’t; no

— swim in the river?
— oh, no. Our teacher told us here. It’s dangerous.
A. Why don’t; not swim
B. Why not; not to swim
C. Why not; don’t swim
D. Why don’t; don’t swim

A. Why don’t; not swim(答案→)B. Why not; not to swim C. Why not; don’t swimD. Why don’t; don’t swim解析：为什么不在河里游泳，why not do sth后面加动词原形，表示建议通常与hou about doing sth what about doing sth why don't you do sth进行同一句转换肯定的表达是tell sb to do sth 告诉某人去做某事，否定的表达是tell sb not to do sth告诉某人不去做某事。故选B，根据下句老师告诉我们不要在那游泳。

我明天再问问老师，叫他解释下这个问题