So far scientist have not ___ to successfully devise a ...

[ Modals ]

So far scientist have not ___ to successfully devise a mechanism

A. been able

B. need

C. must

Select your answer:
A B C D E

Other quiz:

Tenses › View

They _______football match on TV at 7pm yesterday

A. are watched

B. watched

C. watches

D. are watching

Grammar › View

The little boy _______ four bananas!

A. eight

B. ate

Grammar › View

What is the correct abbreviation for October?
A. Octo.
B. Oct.
C. Oct
D. Octob.

Indefinite Pronouns › View

______ bought me a drink yesterday.

A. Something

B. Everybody

C. Someone

D. Somewhere