[ Tenses ]
Environmental pollution ____ ever since people ____ to gather together in towns and cities.
A. has existed / are beginning
B. had existed / were beginning
C. exist / have begun
D. has existed / began
Select your answer:
Random Topics:
Comparative AdjectivePreposition on TimeClause Markers TOEFL GrammarSentence Adverbs & Third ConditionalGrammar RulesAdjectives & QuantifiersPassive Voice with ModalsArticle and Order of AdjctiveRelative Pronoun/AdverbsInversions and SubjunctiveOther quiz:
Tenses › ViewI lost my phone when I _____ in the park yesterday.
A. am walking
B. walks
C. walked
D. was walking
Grammar › View
Employees are encouraged to voice their concerns ____ anonymity to promote open communication.
A. in
B. under
C. with
D. on