[ 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 › ViewHe has to _________________ the plants twice a day.
A. water
B. waters
C. watering
D. watered
Grammar › View
The program is ___________ the TV
A. in
B. on
C. at
D. within
Articles › ViewI’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