The first laser ------- in 1960 by Maiman almost half ...

[ Grammar ]

The first laser ——- in 1960 by Maiman almost half a century after the publication of Einstein’s theory of radiation which ——- the possibility of laser operation.

A. has been demonstrated / had shown

B. had been demonstrated / showed

C. was demonstrated / showed

D. demonstrates / was shown

E. was being demonstrated / shows

Select your answer:
A B C D E

Random Topics:

Grammar - may/might/could Gerund or to Infinitive TOEIC Grammar Perfect Verb Tenses Simple Present and Present Continuous Grammar: was/were English Morphosyntax Adverbial Phrases Past Simple Tense Passive Modals, Impersonal Passive

Other quiz:

Grammar › View

After _________ long day, ______ cup of tea was great!!

A. the / the

B. a / a

C. the / a

Present Tense vs Past Tense › View

I ____________ the drama club last year.

A. join

B. joining

C. joins

D. joined

Vocabulary and Grammar › View

He is very ill, and the doctors are not sure whether he will _____ it through the night.

A. last

B. survive

C. endure

D. make

Gerunds and Tenses › View

. Which sentence shows a future plan?

A. I go to the doctor tomorrow.

B. I will go to the doctor tomorrow.

C. I am going to the doctor tomorrow.

D. I going to the doctor tomorrow.