[ Tenses ]
While they (study), the lights went out.
A. While they were studied, the lights went out.
B. While they were studying, the lights went out.

Random Topics:
Simple present/ past/ future tenseVerbs + Infinitives / GerundsPresent TensesIntermediate GrammarTransitional WordsFuture - be going toPast Continues TenseParts of Speech and GrammarMust or Mus notPast Simple vs Present SimpleOther quiz:
Mixed General Quiz › ViewI wish you … tomorrow
A. will go
B. shall go
C. would go
D. have gone
Grammar › View
The sun ___ in the east and sets in the west.
A. rise
B. rises
C. rising
D. rose
Grammar and Structure › ViewSpain _________ at one time a very powerful country.
A. was
B. is
C. has been
D. was being
Vocabulary & Grammar › View
The rivers in this area are seriously polluted ____________ harmful waste from factories.
A. such as
B. because
C. because of
D. except for
