Question

【题目】Parents must let their children ______ about the danger of swimming in the river.

A. know B. knew C. knows D. to know

Answer 1

【答案】A

【解析】句意：父母必须让他们的孩子了解在河里游泳的危险。let sb do sth让某人做某事，故此处用动词原形know。故选A。