Which statements describe the movement of blood through the heart? check all that apply.

blood from the veins enters the ventricles.

atria and ventricles contract at the same time.

atria push blood into the ventricles.

valves allow for two-way blood flow.

ventricles push blood out of the heart.

Before the can be observed by using a transmission electron microscope, cells are sliced into very thin sections. what disadvantage does this procedure present in the study of cellular parts

The many stone tools, fragmentary animal bones, and teeth found at gran dolina, spain, indicate that hominids there? a. processed and consumed animals and other hominids. b. did not differ appreciably from earlier asian homo erectus. c. were similar to later homo sapiens. d. none of the above

Which statement does lola need to correct, and why? a) statement 1 because spiral galaxies do not havearmsb) statement 2 because the bulges contain mostlyyoung red stars. c) statement 3 because the arms are made of mostlyyoung blue and blue-white stars. d) statement 4 because spirals galaxies contain littleto no dust.(c)