What is the primary function of skin cells? OPTIONS:
- to deliver messages to the brain
- to generate movement of muscles
- to provide a physical barrier to the body
- to produce carbohydrates for energy
A: to provide a physical barrier to the body

The main function of a duck's webbed feet is to help the duck OPTIONS:
- make noise
- protect itself
- swim in water
- find a mate
A: swim in water

When a red bull (RR) is bred with a white cow (WW), a roan calf (RW) is sometimes produced. If a roan bull (RW) is bred with a roan cow (RW), what is the most likely outcome of the offspring? OPTIONS:
- 1 red, 1 white, and 2 roan
- 0 red, 1 white, and 3 roan
- 2 red, 2 white, and 0 roan
- 0 red, 0 white, and 4 roan
A: 1 red, 1 white, and 2 roan

Some meteorologists use visual aids such as diagrams, maps, and charts when they present the weather to television viewers. How do different types of visual aids help the viewers understand complex weather phenomena? OPTIONS:
- by combining knowledge from past reports with new information
- by providing information collected by other meteorologists
- by checking the accuracy of each part of the weather report
- by showing many components that impact the weather
A:
by showing many components that impact the weather