Driving through snowstorm on icy roads for long distances is a most nerve-racking experience. It is a paradox that the snow , coming【C1】______gently , blowing gleefully in a high wind , all the while【C2】______down a treacherous carpet,freezes the windows,【C3】______the view. The might of automated man is【C4】______. The horses, the powerful electrical systems, the deep-tread tires, all go【C5】______nothing. One minute the road feels【C6】______, and the next the driver is sliding over it, light as a【C7】______, in a panic , wondering what the heavy trailer trucks coming up【C8】______the rear are going to do. The trucks are like【C9】______when you have to pass them,not at sixty or seventy【C10】______you do when the road is dry,but at twenty-five and thirty. 【C11】______their engines sound unnaturally loud. Snow, slush and【C12】______of ice spray from beneath the wheels,obscure the windshield, and rattle【C13】______your car. Beneath the wheels there is plenty of【C14】______for you to slide and get mashed to a pulp. Inch【C15】______inch you move up,past the rear wheels, the center wheels, the cab, the front wheels, all【C16】______too slowly by. Straight ahead you continue, 【C17】______to cut over sharply would send you into a slip,【C18】______in front of the vehicle. At last, there is【C19】______enough, and you creep back over, in front of the truck now, but【C20】______the sound of its engine still thundering in your ears.
【C1】

A. up
B. off
C. down
D. on