How does the amount of the Sun's energy the Earth receives change throughout the year?

A. Decreases in the Northern Hemisphere in July

B. Decreases in the Southern Hemisphere in July

C. Increases in the Southern Hemisphere in January

Asample of digestive juice was removed from the stomach of a pig. the juice was placed in a test tube along with some grains of wheat. a second test tube was set up containing an equal number of wheat grains, with distilled water rather than digestive juice. the test tubes were kept for 8 hours at 40 degrees c. after 8 hours, the grains inside the digestive juice had broken into tiny particles. the grains of wheat, in the water, were wet but otherwise unchanged. what is the control group?