I need help! I don't know if my answers are wrong or right. I want to submit my homework with correct answers.

Often on a topographic map, every fifth contour line is darkened. what is this line called? a. key b.slope c.benchmark d. index contour

Which element forms an ionic bond with flourine? 1) fluorine 2) carbon 3) potassium 4) oxygen

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.