Explain giant covalent, intermolecular,

Giant covalent substances have many atoms joined together by covalent bonds. Diamond, graphite and graphene are forms of carbon with different giant covalent structures.

Giant molecular are structure such as graphite or diamond. All bonds are through covalent. They have the same bond throughout the structure without changing.

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.