[ Modal Verbs ]
They __________ known about the event if they had checked their emails.
A. must have known
B. could have know
C. could have known
D. must have knew

Random Topics:
Simple Future - WillQuestion WordsGrammar PhrasesPerfect TensePresent Forms and Narrative TensesActive vs. Passive VoicePresent Simple and Present ContinuousVerb AgreementAdverbial Clause of MannerPrepositionsOther quiz:
Verb Form › ViewThere’s no point in __________________ the matter. He has already made his decision.(discuss)
A. discuss
B. to discuss
C. discussing
D. having discussed
Simple Tenses › View
The guard ________ off the hallway lights every morning.
A. switch
B. switches
C. switchs
D. switched
Conjunctions › ViewDo you want to eat pasta ___________ rice for dinner?
A. and
B. but
C. because
D. or
Vocabulary › View
He is a faithful friend, and always support me when things go wrong
A. Ambitious
B. Care
C. Loyal
D. Sociable
