Many Yoga exercises involve putting the body into difficult positions. Some of them are very hard to learn. Have you ever tried to fold your legs over one another? This is one of the basic Yoga positions. It is called the lotus position.

许多瑜伽练习都涉及到把身体置于困难的姿势。它们中有些东西很难学习。你有没有尝试过把腿折起来呢？这是瑜伽的基本姿势之一。它被称为莲花的位置。

Many Yoga exercises involve putting the body into difficult positions=许多瑜伽练习都涉及到把身体置于困难的姿势。

备注：“把身体置于困难的姿势” 只是“瑜伽很多练习动作” 中的“ 其中一个动作”

【1】involve doing sth 需要/包括/牵涉到做某事

 Nicky's job as a public relations director involves spending quite a lot of time with other people.  

尼基作为公共关系主管，需要花很多时间与别人打交道。

 【2】need doing sth=need to be done 需要做某事  (用主动结构表示被动含义)

Your room needs cleaning once a day.=Your room needs to be cleaned once a day.

你的房间需要每天打扫一次。

involve  vt.包含；需要；使成为必然部分（或结果）(英文解释if a situation, an event or an activity involves sth, that thing is an important or necessary part or result of it）

单词involve作为及物动词，后可以接名词或者动名词作宾语

 【1】involve +名词(sth)

Any investment involves an element of risk.任何投资都有一定的风险。

Many of the crimes involved drugs.许多罪案都与毒品有关。

【2】involve+动名词(doing sth)

The test will involve answering questions about a photograph.

考试将包括回答一些关于一张照片的问题。