[ Grammar ]
The pilots have …… them many times
A. Did
B. Done

Random Topics:
Coordinating ConjunctionVerb Forms and PrepositionsA/AnPhrases & ClausesUsed to & would & Past SimpleTenses and Passive VoiceFuture Continuous, Future Perfect and Future Perfect ContinuousPast Simple and Past ProgressiveHas and HaveModal Verbs & Time PrepositionsOther quiz:
Verb Tenses › ViewForm a sentence using past continuous tense.
A. They were playing basketball.
B. She was studying for her exam.
C. He was cooking dinner.
D. She is studying for her exam.
Modal Verbs › View
My back has been hurting for weeks. I__________go to the doctor’s.
A. don’t have to
B. have to
C. mustn’t
D. must
Grammar › ViewI have studied ____________ six hours. Now I am going to have lunch.
A. during
B. for
C. since
D. within
Many vs. Much › View
I can’t wait for Max. I haven’t got …………………….. time.
A. Enough
B. Too much
C. Too many