He jumped into the water when he heard a boy__(call) for help.为什么?

题目

He jumped into the water when he heard a boy__(call) for help.为什么?

答案

calling
hear sb do sth和hear sb doing sth.
hear sb do sth表示“听到某人做了某事”,hear sb doing sth.表示“听到某人正在做某事”,这题目用doing形式最好,强调动作正在发生.
一些感观动词如hear, see, feel, watch等后面既可以接宾语+do sth, 也可接宾语+动词-ing形式构成复合宾语.根据情景及句意的需要许多时候只能用一种,但有时两者都可用而意义没多大区别.