As the pulses interfere destructively there is a point in time when the string is perfectly straight. which of the following statements is true at this moment? a)the energy of the string is zero. b)the string is not moving either up or down. c)the string has only kinetic energy.

show the wavelengths of a wave. show the crests of a wave.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.