Explanation:
The purpose of visual aids is to explain an idea visually that cannot be expressed easily verbally. They should not be merely something for the audience to look at, but rather created carefully and presented effectively.
Answer:
B. complex; Although most flash mobs gather to make a statement, some gather to protest something.
Explanation:
A complex sentence consists of an independent clause, which can stand on its own, and at least one subordinate clause, which does not express a complete thought. Besides, a dependent clause usually begins with a subordinate conjunction, such as <em>after before </em>and <em>because, </em>and is separated from the independent clause by a comma.
In the sentence given, the dependent clause is: <em>Although most flash mobs gather to make a statement. </em>Meanwhile, the independent clause is: <em>some gather to protest something.</em>