Which one of the following is a characteristic of a metal?
a. changes the color of litmus paper to red
b. reacts with bases to produce salts
c. becomes negative when combined with other elements
d. conducts heat readily

Providing immunity by injecting the body with a weakened form a pathogen is known as

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere

The polio virus can cause skeletal muscle paralysis by destroying neuron cell bodies. what area of the spinal cord is destroyed