Acid rain can be caused due to combustion of fossil fuels or erupting volcanoes or rotting vegetation which ____ sulfur dioxide and nitrogen oxides into the atmosphere.
C. is releasing
D. have released
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Principal vs. Principle Relative Pronoun Future Perfect Tense To Infinitive or Bare InfinitiveGrammar, Conditional Sentences, VocabularyComparative and Superlative AdverbsPositive and Negative ConnotationsGrammar ClausesTenses - Auxiliaries
Other quiz:Past simple - Irregular Verbs › View
A long time ago, the pirates —————-(find) a treasure.
Grammar › View
What is the simple subject of the sentence?
The dusty book sat on the top shelf.
A. The dusty book
D. sat on the top shelf.
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