4. What is a common feature of both active and passive immunity? A They are acquired by vaccination. B They are always short-tem. C They involve the activity of memory cells. D They involve antibodies.

Need the diagram below, which is not drawn to scale, shows the position of the earth, moon, and sun. what type of eclipse occurs when the earth, moon, and sun are lined up in the order shown? a. planetary eclipse b. solar eclipse c. martian eclipse d. lunar eclipse

Why are current extinctions of concern to enviromentalists?

High blood pressure occurs when there is too much blood flowing through the blood vessels at one time. by changing the amount of water in the blood, blood pressure can change. the excretory system can to lower blood pressure.which would most likely occur in the kidney? a)more water would be transferred from the nephron.b)less water would be absorbed into the nephron.c)the amount of water in the bladder would decrease.d)the amount of water in the blood would increase.