[ Tenses Usage ]
The scientist _____ solutions to clean polluted rivers when she discovered a breakthrough.
A. researched
B. was researching
C. had researched
D. is researching
Random Topics:
ApologizingCoherent Sentence with Correct Grammar StructureSimple, Compound, Complex SentencesModals and AdvicePresent Simple and Present Continuous TenseReported Speech and Reported QuestionsPast Perfect & Past Simplemust/shouldPrepositions of Place & TimeKnee AnatomyOther quiz:
Grammar › ViewWhich word should replace the underlined word in the sentence?
I worryed about our safety.
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A. woriied
B. worried
Present & Past Tenses › View
Nukmi : What was your sister doing when you arrived home last night?
Rendra : She … in the kitchen.
A. was cooking
B. cooks
C. has cooked
D. is cooking
E. has been cooking
Grammar › ViewWhich of the following is a proper noun?
A. city
B. dog
C. Paris
D. book
Grammar › View
Choose the correct conjunction to complete the sentence:
I couldn’t hear _____ could I see the speaker.
A. and
B. nor