[ 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:
Random Topics:
Some vs. Any Type of SentencesExpressing WishesPaired ConjunctionPast Simple - Present PerfectVerbs + Gerund or InfinitiveQuantifiers with NounsNouns and QuantifiersSimple Future - Will
Other quiz:
Adverbial Clauses › View__________ the exam, concentrate on what you have to answer.
A. Before
B. Unitl
C. During
Relative Clause › View
That’s the annoying man ………………. was whistling during the film.
A. who
B. which
C. where
D. what
How to use : Read the question carefully, then select one of the answers button.