What does a key part mean?

“关键部分”是什么意思？

Portsmouth Square is also a key site.

朴次茅斯广场也是一个重要地点。

A maths book, an English book, two storybooks, a key, some candies and three pens.

一本数学书、一本英语书、两本故事书、一把钥匙、一些糖果和三支笔。

The new People's Republic of China saw Dr Lin Qiaozhi playing a key role.

新中国看到林巧稚医生发挥了关键作用。

It is not only good for our health, but also a key part of many cultures.

它不仅对我们的健康有益，而且是许多文化的重要组成部分。

A notebook, a key, an English book, a maths book, some candies, two pens and two storybooks.

一本笔记本、一把钥匙、一本英语书、一本数学书、一些糖果、两支笔和两本故事书。

You need a key to get in.

你需要钥匙才能进去。

He used a key to open the door.

他用钥匙开启了门。

He unlocked the door with a key.

他用钥匙解锁了门。

He used a key to unlock the door.

他用钥匙解锁了门。