[ Modal Verbs ]
Scientists fear that a patient’s immune system _____ stem cells unless they _____ genetically identical to the patient’s other cells.
A. may reject / are
B. may have rejected / were
C. could reject / had been
D. has rejected / has been
E. would be rejected / were
Random Topics:
TimePrepositions after Verbs and AdjectiveModals and Semi-ModalsGiving and Asking for AbilityPrepositions and ArticlesZero & First ContidionalHas and HaveGerunds as Objects of PrepositionsWill vs Verb InfinitivesConjunctionsOther quiz:
Grammar › View
The mouse is ________ the box.
A. between
B. behind
C. under
D. next to
Verb › View
My brother and I have hiked for more than 100 miles this year.
A. Past Tense
B. Present Tense
C. Future Tense
D. Past Perfect Tense
E. Present Perfect Tense
I’m a fun-loving person. I love ____ parties and dancing!
A. a
B. an
C. the
D. –
Subject Verb Agreement Irregular Verb › View
You _____ the funniest person.
A. is
B. are