ant

我看到一只蚂蚁在地上爬。

I saw an ___ant crawling on the ground.

他非常温柔，连一只蚂蚁都不会伤害。

He is so gentle that he wouldn't hurt an ___ant.

他非常温柔，连一只蚂蚁都不忍伤害。

He is so gentle that he couldn't hurt an ___ant.