<span>None of the light passes through it; some of the light is absorbed as heat but most is reflected off the surface. This is how you see </span>objects. reflected light from them hits your eye. (Opaque means not transparent)
<span>The purpose of pumping is to increase overall velocity. The person drops down into a crouch while traversing the more-or-less flat bottom of the U-shaped pipe or bowl. Then, as he enters the sloped part of the ramp or bowl, called the transition, he straightens his legs and rises up. By raising his center of mass just at the beginning of the arc, the person gains energy and thereby increases his speed.</span>
Downwards - from uphill towards the lowlands and eventually into the sea.
