step on it

例句：

1. 1.Don't step on it; it's fragile.
   不要碰它，它很脆弱。
2. 2. The dog stepped over the fence and ran into the neighbor's yard.
   狗跳过了围栏，跑进了邻居的院子里。
3. 3. Please step in when you see someone in trouble.
   当你看到有人陷入困境时，请伸出援手。