1.
is the placement of the adjective clause in the sentence correct or incorrect?
this year's fireworks show must have been expensive, which is an annual holiday tradition.
a. incorrectly placed
b. correctly placed

The answer is A, it is incorrectly placed. Because if placed this way, it is unclear what the remaining part of the sentence (which is an annual holiday tradition) actually refers to - the show or expensive. It is ambiguous. Thus the correct way to write this sentence would be: This year's fireworks show, which is an annual holiday tradition, must have been expensive.

This is a compound sentence because it uses fanboys the s stands for since.