Logic of a solution: *Carbon may be stored in sedimentary rock for millions of years. Sedimentary Rocks One of the commonest sedimentary rocks is sandstone. Carbon may be stored in sandstone for millions of years.*
*(C)*
The original question: *What element may be stored in sandstone for millions of years?
Options:
- (A) copper
- (B) calcium
- (C) carbon
- (D) chemicals
- (E) heat
- (F) iron
- (G) rock
- (H) fossils*

Line 1: *Most modern gymnosperms are trees with woody trunks. Conifers are examples of gymnosperms. Conifers are trees with woody trunks.*
*(A)*
Line 2: *What is a tree with a woody trunk?
Options:
- (A) conifer
- (B) orchids
- (C) plants
- (D) trees
- (E) less water
- (F) vines
- (G) lycophytes
- (H) ferns*

Logic of a solution: *Plants use cellulose for their cell walls. Basically, fiber is cellulose . Cells walls are fiber.*
*(F)*
The original question: *What are cell walls made of?
Options:
- (A) fossils
- (B) peat
- (C) moss
- (D) cations
- (E) Carbon
- (F) Fiber
- (G) Fungi
- (H) sodium*

Line 1: *Vertebrates are animals that have a backbone. Vertebrates generally have a backbone called the spinal column. Vertebrates are animals that have a spinal column in their skeletal system.*
*(B)*
Line 2: *If an animal has a spinal column in their skeletal system what is it called?
Options:
- (A) skeletal animal
- (B) vertebrate
- (C) A Greek letter
- (D) invertebrated
- (E) organ
- (F) critical organs
- (G) spined animal
- (H) epidermal*

Logic of a solution: *Ethologists usually study how animals behave in their natural environment. Many ethologists capture their observations on videotape or audio tape. Scientists who study how animals behave use videotape or audio tape.*
*(A)*
The original question: *Scientists study animal behavior through which of the following?
Options:
- (A) audio and video tape
- (B) Electrical energy
- (C) irradiation
- (D) A computer
- (E) raising their temperature
- (F) Something coming from a gland
- (G) The bending of a ray of light
- (H) characteristics*

Logic of a solution: *Arteries generally carry oxygen-rich blood. Arteries carry blood away from the heart. Something that brings blood away from the heart carries oxygen-rich blood.*
*(H)*
The original question:
*What direction does something that has oxygen-rich blood go?
Options:
- (A) mouth of rivers
- (B) the body's largest organ
- (C) move to different locations
- (D) Earth orbiting the Sun
- (E) Move to another area
- (F) to move people
- (G) animal transport
- (H) Away from the heart*