The researchers ....................... hard to develop a perfect new model ...

[ TOEIC Grammar and Vocabulary Review ]

The researchers ………………….. hard to develop a perfect new model over the last two years.

A. work

B. worked

C. are working

D. have been working

Select your answer:
A B C D E

Other quiz:

Grammar › View

I haven’t been to the beach the _______summer.

A. every

B. all

C. whole

D. each

Conditional Sentences › View

If I go on a diet

A. I’ll buy you some sweets.

B. I’ll lose weight.

C. we’ll go for a picnic.