A real important part of the butterfly stroke is the under water swimming, fly kick under water.

蝶泳非常重要的组成部分是水下部分，即水下蝶泳腿。

youdao

A real important part of the butterfly stroke is the under water swimming, fly kick under water.

蝶泳非常重要的组成部分是水下部分，即水下蝶泳腿。

youdao