[ Modals for Obligation ]
You _____________________ pay attention in class.
A. must
B. mustn’t

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So, Such, Many, MuchRelative & Interrogative PronounsPast Perfect vs Past SimpleModal Verbs of PermissionPresent tense AffirmativeGrammar and Verb TensesCountable & Noncountable NounsModal Verb Gerund or To InfinitivePast and Present Continuous tensePossessive PronounsOther quiz:
Homophones › ViewJohn volunteers at a senior center reading the residents’ mail (allowed, aloud) for them.
A. Allowed
B. Aloud
Modals and Phrases › View
Rick didn’t use to be a good swimmer, but he trained hard and won an important race. Now he’s a _____!
A. successful
B. success
C. talented
Vocabulary › ViewTaking responsibility for one’s own actions
A. Accountability
B. Conscience
C. Temperance
D. Beneficence
Grammar › View
Yuri Gagarin was one of the pioneers of space _____.
A. exploration
B. explorer
C. exploring
D. explorers