[ Grammar ]
All passengers ______ show their passports to the officer.
A. can
B. must
C. have to
D. should

Random Topics:
Modal PerfectBe going to / WillComparatives and Past Perfect TenseBe used to vs used toPassive with ModalsFrequency AdverbsSimple Present & Present ProgressiveIndirect SpeechPhrasal Verbs and Verb FormsFor vs SinceOther quiz:
Present Perfect Tense and Simple Past Tense › ViewA: Do you know where Adam is?
B: Yes, I’ve ___ seen him. He’s in the kitchen.
A. just
B. never
C. already
D. ever
Grammar › View
X: I think every child should play a sport.
Y:
A. Really? I don’t.
B. Neither do I.
C. Oh. I do
Tenses › ViewHe bought a new laptop ______ on his projects.
A. for work
B. by working
C. to work
D. worked
Grammar › View
No matter what happens, ____ should always be honest. It is our Chinese traditional moral value.
A. it
B. one
C. they
D. he
