Answer:
When cells communicate by the signaling process, one cell produces a <u><em>signaling molecule</em></u> that must be received by the <u><em>signal receptor </em></u>on or in the responding cell.
s would be secondary Explanation:
just cause
Answer:
A
Explanation:
They form in mountains and flow through mountain river valleys. Glaciers cause erosion by plucking and abrasion.
The amount of money a family makes annually