Which two substances have no fixed shape and no fixed volume? A: crystalline solid and noncrystalline solid
B: noncrystalline solid and liquid
C: plasma and liquid
D: gas and plasma

which statement about this sum is true? −245+2.7

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​

the independent variable, or the one that is intentionally manipulated is the speed.

i think the answer is a, hope this : )