用括号里的词填句子要适当形式的 She hs a nice voice .I often hear her----(sing) in the morning.

问题描述:

用括号里的词填句子要适当形式的 She hs a nice voice .I often hear her----(sing) in the morning.
我写的是sing 但是答案是singing 为什么

填singing,意思是只听到她唱歌的片段,而不是整个过程.
如果填sing,意味着她唱歌的整个过程都听到了.