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:

Random Topics:
Past Continuous Tense & Past Modals Simple Tenses Types of Sentences Subjective and Objective Pronoun Will vs be going to Present & Past Tenses Grammar - Place and Movement Intermediate Conditional Sentence Type 2 and Type 3

Other quiz:

Grammar › View

Used to name a specific person, place, or thing. These begin with a capital letter.

A. common nouns

B. concrete nouns

C. proper nouns

D. abstract nouns

Vocabulary › View

What is the primary function of a hydrant?

A. To generate electricity

B. To record historical events

C. To provide water access

D. To synchronize activities