[ Tenses Usage ]
None of the renewable energy sources _____ completely free from environmental impact.
A. is
B. are
C. has been
D. have been
Select your answer:
Random Topics:
Family VocabularyAdverb ClauseVocabulary, Grammar, SpellingModals and InversionPast Progressive TenseConnectives (because, due to, owing to, because of)Vocabullary TestVerb FormBecause / soOther quiz:
Prepositions › ViewMy mother will not come ……………… 3:30 because she leaves her office at 3:00.I think she is on her way to us.
A. For
B. Before
C. After
D. In
Present Perfect Tense › View
We have lived here _______________ 10 years
A. for
B. since
C. in
D. on