All of the following sentences are complex EXCEPT

A) Even though acid rain can have damaging effects, few people know much about it.
B) Acid rain has been studied as an environmental issue by the government since the 1970s.
C) Since they erode statues and corrode steel structures, the chemicals in acid rain are harmful.
D) Since the Industrial Revolution began, emissions of sulfur dioxide and nitrogen oxide have increased.

I know it is not c or a. But I think it is d.

Complex sentence = 1 independent clause + at least 1 dependent clause

The intro words "since" and "even though" usually introduce dependent clauses -- IF there's a subject and verb that go with it.

In which sentence is there NOT a subject and verb that go with "since"?

Oh I understand now. Thank You!

You're welcome. =)

All of the following sentences are complex EXCEPT

A) Even though acid rain can have damaging effects, few people know much about it.
B) Acid rain has been studied as an environmental issue by the government since the 1970s.
C) Since they erode statues and corrode steel structures, the chemicals in acid rain are harmful.
D) Since the Industrial Revolution began, emissions of sulfur dioxide and nitrogen oxide have increased.

To determine which sentence is not complex, let's first understand what a complex sentence is. A complex sentence is made up of an independent clause, which can stand alone as a complete sentence, and one or more dependent clauses, which cannot stand alone as complete sentences.

Option A) "Even though acid rain can have damaging effects, few people know much about it." This sentence has an independent clause ("few people know much about it") and a dependent clause ("Even though acid rain can have damaging effects"). It is a complex sentence.

Option B) "Acid rain has been studied as an environmental issue by the government since the 1970s." This sentence only contains one independent clause and no dependent clauses. It is a simple sentence, not a complex sentence.

Option C) "Since they erode statues and corrode steel structures, the chemicals in acid rain are harmful." This sentence has an independent clause ("the chemicals in acid rain are harmful") and a dependent clause ("Since they erode statues and corrode steel structures"). It is a complex sentence.

Option D) "Since the Industrial Revolution began, emissions of sulfur dioxide and nitrogen oxide have increased." This sentence only contains one independent clause and no dependent clauses. It is a simple sentence, not a complex sentence.

Therefore, the sentence that is not complex is Option B) "Acid rain has been studied as an environmental issue by the government since the 1970s."