中国大学MOOC: You must check-in at least one hour before _____ (depart) time.
举一反三
- You must check ( )at the airport an hour before your flight takes off.
- Please ( ) at least an hour before departure (起飞). A: take in B: take out C: check in D: check out
- Passengers must _____________ at the airport an hour before the train leaves. A: check out B: check in C: checking D: check over
- You try to check in online at least an hour beforehand. A: should B: shouldn't
- You must_________at the airport an hour before your plane leaves. A: check in B: check out C: check with D: check over