According to the passage wind is ______.

A．Wind makes cold air higher and warm air lower.
B．Wind can even carry cars and trucks to the sky.
C．Wind makes all kinds of plants and flowers moving.
D．Wind moves clouds in the sky and brings about rain.

A．it's great fun for people to fly a kite in light wind
B．what is wind
C．high winds are very dangerous
D．people can feel wind, hear wind but can't see wind