For research and getting animals for a zoo
The students in Cassie's school took a field trip?
Oh, I see. There's probably a passage I need to read.
Lieutenant is not a part of the main clause, and it is an address to a person that is inserted into the sentence. It must be therefore separated by comas on both sides: the correct answer is a.
Charlie is afraid because he knows that the same thing will happen to him.
