问题详情：
—It is so hot today. Why not swim in the river?
—No, we can't swim in the river. Our teachers and parents always warn us ________in the river. It's too dangerous.
A．to not swim B．swimming C．not to swim D．not swimming
【回答】
C
【解析】
句意：——今天太热了。为什么不在河里游泳呢？——不，我们不能在河里游泳。我们的老师和父母总是*告我们不要在河里游泳。这太危险了。
考查动词不定式的否定形式。*告某人不要做某事warn sb. not to do sth或warn sb. against doing sth，结合选项，可知用warn us not to swim in the river “*告我们不要在河里游泳”，故选C。
知识点：动词和动词短语
题型：选择题
