[ Tenses Usage ]
None of the renewable energy sources _____ completely free from environmental impact.
A. is
B. are
C. has been
D. have been
Random Topics:
Dependent PrepositionsApologizingTenses and Verb FormsGrammar - used toEs and SUnreal ConditionalsFuture - Will and Be going toTenses and ArticlesWill & Be going toComparatives, Superlatives, and ModalsOther quiz:
Vocabulary & Grammar › View‘Sorry. Did you say something?’
‘Yes, I asked you ________ me the salt.’
A. passed
B. to pass
C. please pass
D. passing
Grammar › View
Clive is the man ___ my cousin Lucy.
A. married
B. which married
C. who married