leap in

• • 跳进：

    The despairing girl went to the well and leapt in.

    绝望的女孩走到井边，然后跳了进去。

  • 紧急行动；突然行动：

    While other people were turning over the matter, he leapt in with his proposal.

    当别人还在再三考虑这件事时，他迅速提出自己的建议。