Identify the adverb that modifies the verb
have you ever rafted down the chattanooga river?
a) have
b) you
c) ever
when rafting, you must always wear a life jacket.
a) when
b) always
c) life

1. The adverb that modifies the verb is c) ever. Without it, it wouldn't be completely clear as to which time frame the speaker refers to. It may have been for example the last year, or in some other particular moment.

2. The adverb that modifies the verb is b) always. It adds to the sense of urgency of wearing a life jacket when rafting. Without it, the meaning of this sentence wouldn't be so precise.