The Storage tank for bile is the?

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

What does it mean for a cell membrane to be selectively permable

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons