Plz help i have an hour

Out of the seven main animal groups (fish, mammals, birds, insects, reptiles, amphibians, and arachnids), how many contain members with internal backbones? a. 5 b. 3 c. 7 d. 1

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water

Prior knowledge can be gained from personal experience and a) forming well-developed hypotheses. b) listening to opinions of other people on a topic. c) researching previous experiments and results on a topic. eliminate d) no other methods. it can only be gained by personal experience.