Which of the following describes a properly controlled experiment?
a. five radish seeds are planted in an outdoor garden that gets lots of sun and water.
b. fifteen turtles are fed iceberg lettuce and vitamins, while another fifteen turtles are fed only iceberg lettuce.
c. a poll is taken to determine the most popular web site ever.
d. twenty mice are fed doughnuts every day and their weight is measured after two months.

Fifteen turtles are fed iceberg lettuce and vitamins while another fifteen turtles are fed only iceberg lettuce. B. 

This is because you are keeping everything the same and only changing one element of the experiment.

1. when the tempature rises,your sweat glands and then springs into action making perspiration. some sweat evaporates with your skin taling heat with it.2.some of the blood pumped by the heart travels by your lungs to get rid of carbon dioxide and pick up oxygen.3.saliva produces by, you drinking water which saliva is 98% of. when mucus builds up in your body it also creates saliva as well as, antibacterial compunds.4.when the core body tempature drops, the shivering reflex is triggered to maintain homeostasis. for example: when you get out the pool you start to shiver because it is cold.