I need help with the first box

The sentence that contains a clause used to modify the verb is:

goeff fell off the ladder into the pool because he was dizzy.

Explanation:

Adverbial clauses, which are dependent clauses that function as adverbs, answer the questions when, where, how, and to what extent (how much or how long) and usually modify verbs, adjectives, and other adverbs. Adverbial clauses begin with some subordinating conjunctions (called trigger words) like "because, before, even though, every time, if," etc.