Snow is a subject of great interest to weather experts. They sometimes have difficulty (1)______ where, when or how much snow will (2)______. One reason is that heavy amounts of snow fall in surprisingly small areas.(3)______reason is that a small change in temperature can mean the difference between snow rain. Just what is snow, anyway? Snow is a form of frozen(4)______. It contains groups of ice particles(5)______snow crystals. These crystals grow from water droplets in cold clouds. They usually grow around dust particles.(6)______ , snow ice appear white. This is because the(7)______we see from the sun is white. Most natural materials (8)______some sunlight. This gives them their color. However, when light(9)______ from air to snow, some light is sent back, or reflected. Snow crystals have many surfaces to reflect sunlight. Yet the snow does absorb a little sunlight. It is this light that gives snow its(10)______appearance.(10分)

1. A.estimate B.Estimating C.being estimated D.estimated