[ Tenses ]
There ____ economies since the beginning of civilization, but as a field of study, economics ____ only recently.
A. have been / develops
B. are / has been developing
C. have been / has developed
D. were / was developing
Random Topics:
How often - long - much - manyAsking & Giving AttentionGrammar RulesGoing To Be and WillPerfect Verb TensesModalPersonificationActive & PassivePositive and Negative ConnotationsVerb Patterns / IngOther quiz:
Modal Verbs & Reflexive Pronouns › ViewYou … smoke on board the plane.
A. mustn’t
B. can
C. don’t have to
D. must
Grammar › View
What do you suggest me to do?
A. asking for an advice.
B. giving an advice.
Grammar › ViewListen! The baby ______ over there.
A. is crying
B. are crying
C. to cry
D. crying
Preposition of Time › View
After I eat dinner, I like to watch TV _____ the evening.
A. in
B. on
C. at