Question

The atmosphere at the party was electrifying．Many people ________ the circle dance．

1. A.
   joined
2. B.
   joined with
3. C.
   joined to
4. D.
   joined in

Answer 1

D
join in指“加入某项活动”；join指“加入某个组织”；join＝become a member of，成为当中的一员。