A student is conducting their science experiment on the effect of caffeine on dogs. He has 3 groups of test subjects. The 1st group of dogs receives plain water. The 2nd group of dogs receives 10 mg of caffeine each, and the 3rd group receives 50 mg of caffeine each. He will measure their activity levels by recording how long each dog runs without stopping, after giving them the pills. What is the dependent variable in this experiment?

The amount of activity  

Explanation:

In an experiment, the independent variable is the variable that the scientist/investigator purposely changes or manipulates, which isn't changed by other variables in the experiment (in this case, the amount of caffeine). On the other hand, the dependent variable is the variable that is being measured or tested during the experimental procedure (this variable is 'dependent' on the independent variable). Finally, the control group is defined as the group of individuals/subjects who do not receive the experimental treatment (in this case, the dogs that receive water).

The amount of activity.

Explanation:

stridor can't collapse a lung.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.