名词

1. 热闹状况;活跃
Activity is a situation in which a lot of things are happening or being done.

2. 活动
An activity is something that you spend time doing.

3. （团体为达到某种目的而采取的）活动，行动
The activities of a group are the things that they do in order to achieve their aims.

1. any specific behavior

e.g. they avoided all recreational activity

2. the trait of being active
moving or acting rapidly and energetically

e.g. the level of activity declines with age

Synonym: activeness

3. an organic process that takes place in the body

e.g. respiratory activity

Synonym: bodily processbody processbodily function

4. a process existing in or produced by nature (rather than by the intent of human beings)

e.g. the action of natural forces
volcanic activity

Synonym: natural processnatural actionaction

5. the state of being active

e.g. his sphere of activity
he is out of action

Synonym: actionactiveness

6. (chemistry) the capacity of a substance to take part in a chemical reaction

e.g. catalytic activity