[ Grammar ]
__________ do birds fly south in winter?
Because it’s warmer there and they can find more food.
A. What
B. When
C. Why
D. Who

Random Topics:
Action VerbModals of ObligationModalsVerbs & Verb TensesConjunctions and PrepositionHave GotTime ClauseTOEIC Grammar and Vocabulary ReviewClause Markers TOEFL GrammarTenses and ConclusionsOther quiz:
Verb Patterns › ViewI promise………………………………………. more patient in the future.
A. being
B. to be
C. be
Modal Verbs › View
Take an umbrella. It __________ rain later, I guess
A. must
B. should
C. might
D. will
Grammar › ViewLook ! A hamster ______ by a cat.
A. is chased
B. is being chased
C. was being chased
D. has been chased
Subject-Verb Agreement › View
In the foreground of the painting _____ two women playing musical instruments.
A. Is
B. Are
