[ Grammar ]
Only when ______ may vehicles cross the train tracks.
A. is the green light on
B. did the green light be on
C. on is the green light
D. the green light is on

Random Topics:
Adjectives with PrepositionComparison Degree & GerundsSpeculation with Modal VerbsGerunds, Infinitives and ParticiplesDependent PrepositionsModifiersClauses and ConjunctionUnscramble SentenceDo / Have / Can - Basic QuestionsPresent Progressive or Present SimpleOther quiz:
Simple Present Tense › ViewMy friends and I … in library. We read some books.
A. is
B. am
C. are
D. do
Passive Voice › View
These cars are produced in Japan
A. Active Voice
B. Passive Voice
Grammar › ViewTake care of our environment, _______ that the future generations may also enjoy it.
A. So
B. And
C. But
D. Yet
Modals Verbs › View
We______ have been crazy.
A. Must
B. Will
C. Should
D. Could
