(04.01 MC) The first heart sound is made by
A- blood moving to the atria
B- blood moving to the ventricles
C- opening of the valve between the atria and the ventricles
D- closing of the valve between the atria and the ventricles

Look at the images of different rocks. which rocks have a fine-grained texture? check all that apply. 1 2 3 4 5

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

Which best describes how the common cold spreads in the human body? a bacteria burst out of normal cells killing them b viruses replicate inside respiratory cells c bacteria inject dna into normal cells d viruses insert dna into bacteria