What has already happened
A: The check-out facilities have been shut down.
B: Security officers have checked the building.
C: Visitors have gathered at the entrance.
D: One of the exits has been locked up.
A: The check-out facilities have been shut down.
B: Security officers have checked the building.
C: Visitors have gathered at the entrance.
D: One of the exits has been locked up.
举一反三
- The teaching building ______ for the whole summer. A: will lock up B: will have been locked up C: will be locked up D: will have locked up
- Many a plan ______ to fight against pollution. A: have been worked out B: have been worked on C: has been worked out D: has been worked on
- Jerry is one of the students who ___ England. A: have been to B: has been to C: have to D: has gone for
- This is one of the best books _______. A: that have been published B: that has been published C: that have published D: that has published
- She is one of the volunteers who ______ greatly praised by the government. A: have B: have been C: has D: has been