on his toes

• adj. 警觉的(随时准备行动的；急欲)

on his toes的用法和样例：

例句

1. That job kept John on his toes.
   那项工作约翰忙个不停。
2. He is in a bad temper this morning; take care not to step on his toes.
   他今天上午心情不好，当心一点，不要触犯他。
3. He was on his toes waiting for the news of his lost child.
   他坐立不安地等待他失踪的孩子的消息。