高考英语复习语法练习语法练习08-动词语气资料.pdf

语法练习 08 －动词语气 B spread throughout the year, If it falls, within one or two months and the rest of the year is dry, those plants may die and a desert may form. Sand begins as tiny pieces of rock that get smaller and smaller as wind and weather wear them down. Sand dunes ( 沙丘 ) are formed as winds move the sand across the desert. Bit by bit, the dunes grow over the years, always moving with the winds and changing the shape. Most of them are only a few feet tall, but they can grow to be several hundred feet high. There is, however, much more to a desert than sand. In the deserts of the southwestern United States, cliffs ( 悬崖 ) and deep valleys were formed from thick mud that once lay beneath a sea more than millions of years ago. Over the centuries, the water dried up. Wind, sand , rain, heat and cold all wore away at the remaining rocks. The faces of the desert mountains are always changing –-very, very slowly as these forces of nature continue to work on the rock. 60. Many plants may survive in deserts when__________________. A. the rain is spread out in a year B. the rain falls only in a few weeks C. there is little rain in a year D. it is dry all the year round 61. Sand dunes are formed when___________________. A. sand piles up gradually B. there is plenty of rain in a year C. the sea has dried up over the years D. pieces of rock get smaller 62. The underlined sentence in the third paragraph probably means that in a desert there is____________. C. nothing except sand D. something else besides sand 63 It can be learned from the text that in a desert____________. A. there is no rainfall throughout the year B. life exists in rough conditions C. all sand dunes are a few feet hi