[ Grammar ]
Scientists think there ________ at least five mass extinctions in Earth’s history.
A. will be
B. are
C. have been
D. has been
Random Topics:
Past Simple - Present PerfectVerb AgreementPassive Voice and ModalsPresent Perfect and Present Perfect Progressive TensesModal Auxiliaries and Similar ExpressionsModal AuxiliariesGrammar - Collective NounsPresent Simple Positive and NegativeGrammar - used toSentence LabelingOther quiz:
Grammar › ViewSpelling. Select the correct answer.
word meaning: Right now, instantly
A. imediately
B. Immediataly
C. Immediatly
D. Immediately
Modals › View
Tim looks so frightened and upset. He _____ something terrible.
A. must experience
B. ought to have experienced
C. should have experienced
D. must have experienced
Vocabulary › ViewWhat is the antonym for “abridge”?
A. Expand
B. Shorten
C. Elaborate
D. Clarify
Grammar › View
Have you ever ________ to China?
A. went
B. go
C. been
D. gone