to start doing something suddenly and energetically, often without stopping to think

When he saw the children fighting, he just dived in to sort it out. 他看见孩子们打起来的时候，连忙介入制止。

When I start a new project, I like to dive right in and see how it works. 开始一个新项目时，我喜欢立刻全心投入，看看情况会怎样。