A compound that has four atoms of hydrogen, two of oxygen, and two of carbon might be

acetic acid has four atoms of hydrogen, two oxygen, and two carbon

? you expect us to answer this? ? this is your schoolwork, i don't think we can with this, i think it would considering being

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: