[ 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 › ViewYou____________ forget to pay the rent tomorrow. The landlord is very strict about paying on time.
A. don’t have to
B. couldn’t
C. mustn’t
Grammar › View
the ears of the dog
A. the dog’s ears
B. the dogs’ ears
C. the dog ears
Which 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