[ 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:
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