1. The brain is considered the most complex body part.
大脑被认为是结构最复杂的身体部位。
2. Each complex body part serves a unique physiological role.
每个复杂的身体部位都承担着独特的生理功能。
3. Scientists are studying how this complex body part functions.
科学家正在研究这个复杂的身体部位是如何运作的。

A: Why is the brain so important?
A：为什么大脑如此重要？

B: Because it is a highly complex body part that controls the body.
B：因为它是一个控制身体的高度复杂的身体部位。

1) An anatomical structure with an intricate organization.

2) A biological component that performs specialized functions.

3) A highly sophisticated organ in a living organism.

1. 复杂的身体部位

e.g.
The heart is a complex body part.
心脏是一个复杂的身体部位。

noun phrase

1. An anatomical part of an organism that possesses a highly sophisticated and intricate structure.