Using lasers to produce extremely short and repeatable pulses of ...

[ Modals ]

Using lasers to produce extremely short and repeatable pulses of light, today scientists ———— events happening in time intervals as short as l.000 trillionth of a second.

A. must have measured

B. were measuring

C. used to measure

D. may have measured

E. are able to measure

Select your answer:

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Other quiz:

Types of Sentence Structure › View

Which one is a compound- complex sentence?

A. My brother and I went to the mall last night, but we didn’t buy anything.

B. This new laptop computer has already crashed twice.

C. I’m happy, even though I don’t make much money.

D. Robert, a friend I’ve known since high school, doesn’t eat meat – so Barbara made a special vegetarian dish for him.

Modal Verb › View

Take an umbrella with you. It ……………. rain later.

A. needs

B. should

C. mustn’t

D. might

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