名词了解，理解; 知识（表示多方面的知识时有复数knowledges这一用法）; 学科; 见闻

1. 知识；学问；学识
Knowledge is information and understanding about a subject which a person has, or which all people have.

e.g. She told Parliament she had no knowledge of the affair.
她告诉议会她对此事并不知情。
e.g. ...the quest for scientific knowledge.
对科学知识的探索

2. 据…所知
If you say that something is true to your knowledge or to the best of your knowledge, you mean that you believe it to be true but it is possible that you do not know all the facts.

e.g. Alec never carried a gun to my knowledge...
据我所知亚历克从来不带枪。
e.g. To the best of my knowledge, Gloria did not make these comments.
据我所知，格洛丽亚没这么说过。

3. 因知道…而放心
If you do something safe in the knowledge that something else is the case, you do the first thing confidently because you are sure of the second thing.

e.g. You can let your kids play here, safe in the knowledge that they won't get sunburn.
你可以放心让孩子们在这儿玩，他们肯定不会晒黑。

名词游乐场; 操场，尤指提供如秋千等设备的户外场地; （某些集体聚会游乐的）园地

1. （学校的）操场，运动场；（儿童）游乐场
A playground is a piece of land, at school or in a public area, where children can play.

2. （某一群体的）游憩胜地，度假场所
If you describe a place as a playground for a certain group of people, you mean that those people like to enjoy themselves there or go on holiday there.

e.g. ...St Tropez, playground of the rich and famous.
圣特罗佩，富豪和名流的游憩胜地

形容词宽敞的; 广阔的; （知识）广博的

1. 广阔的;宽敞的
A spacious room or other place is large in size or area, so that you can move around freely in it.

e.g. The house has a spacious kitchen and dining area.
这座房子有一个宽敞的厨房和用餐区。