Hydrophilic (amino-acid based) hormones: A. bind to cell-membrane receptors on the target cells.
B. always increase the production of cyclic AMP,
C always inhibit the production of cyclic AMP,
D. All of the above are correct.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

a electronegativity decreases beacuse the size of nucleus is bigger.