[ Past Continuous Tense ]
You _____ _______ on the door but I was not at home.
A. were knocking
B. was knocking
C. knock ing

Random Topics:
Grammar - Sentence StructureSentence Structure and Verb TensesToeic VerbEs and SModal Verbs of Deduction and SpeculationAdverbs & to beActive Voice-Present tenseContrastive ConjunctionVerb BESuperlative AdjectivesOther quiz:
Grammar › ViewWhat kinds ___________________ program do you like?
A. of
B. from
C. for
D. to
Perfect Tenses › View
All students had just left the classroom when the math teacher came in.
From this sentence, we may conclude that…
A. the students came late for the math class
B. the teacher cancelled the math class
C. the math class started late that day
D. there was no math class that day
Grammar › ViewOn a night …
there was a big thunderstorm, the friends decided to tell each other frightening stories.
A. when
B. who
C. where
D. which
Relative Pronouns › View
Mary is the person … is very kind.
A. who
B. which
C. whom
D. whose
