I NEED HELP ASAP!! plsss help

How many variables are altered in a good experiment? a.1 b.0 c.2 d.3

Which is an example of a vestigial structure? a. tail of a monkey b. fin of a fish c. flower of a plant d. tailbone of a human

Your two friends just told you what to order for them at the drive through fast food restaurant. you give the order but when the food comes about 10 minutes later, you don't remember what each of your friends ordered your memory of the order was in __ memory. a. semantic b. flashbulb c. long-term d. short-term i think i know but i'm not really sure