How are the kidneys related to the excretory system?
a. the kidneys are a part of the excretory system.
b. the kidneys and the excretory system are exactly the same thing.
c. the excretory system is a part of the kidney organs.
d. the excretory system remove waste, but the kidneys do not.

What do you think car designers do if the damage caused by a crash test is too severe?

When electrons are added to the outermost shell of a carbon atom, it forms--an anion that has a larger anion that has a smaller cation that has a larger cation that has a smaller radius.

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".