By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Answer:
I think it is D. A forest fire
True. Alluvial fans, deltas, and deposition are examples of land formations that are formed from deposits by rivers.
30) is B bec it goin from a low to high concentration every time that happens it requiers ATP.
31)B bec think of a enzyme as a key and a lock only one key will work with one lock and not others. So you see B and the black shape on top of it fits perfectly with. B . Another shape would not. So if it was a different shape the enzyme would not recognize it. The key would not fit the lock.
32) is A it pointing arrows out of the cell so everthing need to go out cell A has more insde then out so think ATP as a force pushing it out. And B there more in then out so it can move out easily: