Why do the polar regions have high albedo?

Liquid water turns into water vapor at which step in the water cycle

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Which of the following is a consequence of urban heat islands? increased precipitation downwind of the city? increased precipitation upwind of the city? decreased winds within the city? increased winds within the city?