Which are features of Copernicus's model of the solar system? Select the three correct answers. A. Earth is fixed to a crystalline sphere.
B. All planets orbit the Sun at the same speed.
C. The planets move in perfect circles.
D. The Sun is at the center.
E. The outer planets move in epicycles.
F. The stars are fixed to an outer sphere.​

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?