Laws were quickly passed so that the child abuse could be checked. The underlined part of the sentence is a/an:

The underlined part of the sentence, "so that the child abuse could be checked," is an adverbial clause.

Step 1: Identify the underlined part of the sentence. In this case, it's "so that the child abuse could be checked."

Step 2: Determine the function of the underlined part. Here, it's modifying the verb "passed" by explaining the purpose or reason for the action.

Step 3: Identify the type of clause or phrase. Since it's providing additional information about the verb and includes a subject ("the child abuse") and a verb ("could be checked"), it's a clause.

Step 4: Determine the specific type of clause. Because it's modifying a verb and providing a reason, it's an adverbial clause.