Covalent network solids typically have __ melting points and __ boiling points. the chemical formula of a network solid indicates choices on 1st and second blank are: high/low. choices on the last are: only the types of atoms/ the actual number of atoms/ the ratio of the types of atoms

The first two are high and im not sure about the last one but it is for sure not only types of atoms hope this helps you out.

Explanation:

The frist 2 are high

The last one is the ratio of the types of atoms

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: