[ Grammar ]
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.
A. release
B. releases
C. is releasing
D. have released

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Grammar › View_________ is John? I can’t find him.
A. Wear
B. We’re
C. Where
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I do not go to ________ theatre very often. I prefer ________ films to ________ plays.
A. a / the / the
B. Ø / Ø / Ø
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A. is able to
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Grammar & Vocabulary › View
Choose the Correct Sentence
A. Listen! The birds sing outside.
B. Listen! The birds are singing outside.
