Logic of a solution: *Amphibians have permeable skin that easily absorbs substances from the environment. All frogs are amphibians. Frogs have permeable skin that easily absorb substances in the environment.*
*(E)*
The original question: *What has permeable skin?
Options:
- (A) goats
- (B) alligators
- (C) animals
- (D) apples
- (E) frogs
- (F) sharks
- (G) humans
- (H) snakes*

Line 1: *Echinoderms lack a centralized nervous system. Echinoderms are represented by the starfish. Starfish lack a centralized nervous system.*
*(A)*
Line 2: *What lacks a centralized nervous system?
Options:
- (A) starfish
- (B) barnacles
- (C) blowfish
- (D) our planet
- (E) humans
- (F) Pesticides
- (G) insects
- (H) sharks*

Logic of a solution: *HIV infects and destroys helper T cells. Scientists agree that HIV causes Aids. AIDS infects and destroys helper T cells.*
*(C)*
The original question: *What infects and destroys helper t cells?
Options:
- (A) swea
- (B) Wasps
- (C) AIDS
- (D) CO 2
- (E) PDAs
- (F) humans
- (G) heat
- (H) anemia*

Line 1: *Most people can survive only a few days without water. Water is everywhere H20. Most people can only survive a few days without H20.*
*(F)*
Line 2: *What do most people need at least a little of every few days to survive?
Options:
- (A) NACL
- (B) UV
- (C) mL
- (D) oxygen
- (E) corn
- (F) H20
- (G) rest
- (H) Hydrogen*

Logic of a solution: *Lipids may consist of fatty acids alone, or they may contain other molecules as well. Lipids Lipids are diverse hydrophobic molecules. Diverse hydrophobic molecules may consist of fatty acids alone.*
*(H)*
The original question: *Diverse hydrophobic molecules may consist of what type of acids?
Options:
- (A) Acids
- (B) solutes
- (C) watery
- (D) three
- (E) cell
- (F) rings
- (G) dry
- (H) fatty*

Logic of a solution: *Roundworms make up the phylum Nematoda. Nematodes are simple roundworms. Nematodes are in the phylum Nematoda.*
*(H)*
The original question:
*What phylum are nematodes in?
Options:
- (A) Most plants
- (B) ferns
- (C) parasites
- (D) Epidermis
- (E) white
- (F) insects
- (G) graptolites
- (H) Nematoda*