[countable]

1. (usually Act) a law that has been made by a parliament
   （议会制订的）法案，法令◆Many companies could be in breach of the Data Protection Act.
   许多公司都可能违反数据保护法。  ➡  regulation ⨁to amend / pass / repeal an act
   修改／通过／废除法案

●be/get ˌin on the ˈact (especially BrE) (NAmE usually get ˌinto the ˈact) (informal) to be/become involved in an activity that sb else has started, especially to get some benefit for yourself
参与；插一手