Topics: 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
Select your answer:
Random Topics:
Future Simple TensesNarrative Tenses & ConditionalsDeterminersBe Going To vs. WillPassive Voice - Present ContinuousBare Infinitive and To InfinitiveFirst Conditional SentenceOffering HelpTime ExpressionsGrammar - help/have/let/makeOther quiz:
Simple Present › View
Does he climb a tree?
A. Yes, he does
B. No, he doesn´t
C. No. he don´t
D. Yes, he do
Indirect Speech › View
Mrs Lee said, “I met Charles two weeks ago.”
=> Mrs Lee said that she met Charles … .
A. two weeks ago
B. two weeks before
C. the next two weeks
D. the following two weeks