[ Grammar ]
Scientists think there ________ at least five mass extinctions in Earth’s history.
A. will be
B. are
C. have been
D. has been

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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:
Vocabulary and Grammar › ViewIf someone is said to be “captivated, fascinated, or held in deep, spellbinding attention,” which term describes their state?
A. Insolently
B. Mesmerized
C. Vehemently
D. Agonizing
Grammar › View
She did the test ……….. I did
A. as bad as
B. badder than
C. more badly than
D. worse than
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
