giỏi anh vào 20;21;22 và 23

`20`. B. read books, play games or listen to their problems

`->` Dẫn chứng: Many students in the USA often spen many hours as volunteers in hospitals... their problems

`21`. C. an organization for boys who no longer have fathers

`->` Dẫn chứng: For boys who no longer have fathers,... called Big Brothers

`22`. C. bringing happiness to others makes them the happiest people

`->` Dẫn chứng: Volunteer believe that some of the happiest people... to others.

`23`. A. Volunteer don't provide classes for children

Cần dịch thì cứ réo nhe