[ 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:
Modal Verbs › ViewI can’t___ the house.
A. buying
B. bought
C. brought
D. buy
All, Both, Neither, None, Either › View
We could ________ walk to school or go by bus. What do you think?
A. neither
B. either
C. both
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
