[ Perfect Tenses ]
He found the front door open although he … it before.
A. had locked
B. has locked
C. will have locked

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Articles and QuantifiersModal Verbs - ObligationGrammar - Capitalization and Possessive NounsModals and PhrasesSentence Structure and Pronoun AntecedentTenses and PronounsModals and AdviceVerb Moods and Vague PronounsWord Form & Verb TenseFamily Vocabulary and GrammarOther quiz:
Conjunctions › View___________ the teacher had arrived, they started their work.
A. As soon as
B. Because
C. If
D. For
Grammar › View
There _____ pictures in the living room
A. Isn’t
B. Don’t
C. Aren’t
D. Doesn’t
Comparative Adverb › ViewMrs. Alvarez sings the _____ of all the employees at the bakery.
A. Loudest
B. Louder
C. Loudly
D. Loud
Past Tenses › View
Where did you ________ the dog last night?
We ________ around the house.
A. walked, walk
B. walk, walk
C. walked, walked
D. walk, walked