[ Vocabulary ]
Pollution can have serious effects_________ the balance of ecosystem.
A. in
B. on
C. to
D. for

Random Topics:
PunctuationsPresent, Past and Future TenseGrammar - Compound SentencesRegular Plural NounsPresent Perfect Tense and Simple Past TenseThere is or There areCountable & Noncountable NounsModals for ObligationPassivisationPresent Simple Affirmative and NegativeOther quiz:
Present Perfect Tense › ViewThat dog has been wonderful _______________ you got it.
A. for
B. since
C. but
D. when
Tenses › View
The recycling center ____ plastic waste tomorrow afternoon.
A. will process
B. processes
C. processing
D. process
Verb Tenses › ViewWe took off our clothes and _____ into the river.
A. jump
B. jumped
C. had jumped
D. were jumping
The First Conditional Sentence › View
If you give my dog a bone he ____________ (burry) it at once.
A. burry
B. burries
C. will burry
D. burried
