1．Digital recording has made ------ a significantly wider dynamic range in recorded music. 为什么是Possible？
2．In addition to painting highly acclaimed portraits, Marry Cassatt was ----- to several major art collectors. An advisor / advised ?
3.livestock 是可数名词么？
4.People feel uncomfortable when the humidity rises over 60 percent because perspiration cannot evaporate quickly enough for the body to rid they/ them of the excess heat. ? &为什么？
5. Alaska ,the largest state of the united states in area , is more than twice the size of Texas. In area 对么？ 可数名词前要有限定词？
6．The Red River, so named because of the red-colored sediment it carries, it is one of the main branches of the Mississippi. 哪错了？
7．When a piano keyboard is substituted for buttons on right side of its occurrence, and interest in them is scientific as well as aesthetic. As well as 能连接句子么？substituted for/ by? 为什么 for 对？
8 ltrasonics is concerned with sound vibrates or waves of a frequency above 20,000cycles per second, the upper range audible to the human ear. 怎么选？为什么？
9．Today ---- little fossil ivory remains comes from Alaska. What? 为什么？
10．Free nitrogen is chemically inert and combines with other elements only since very high temperatures and pressures. 怎么改? 这句话什么意思？
11． Daylight saving time came into useful in the U.S. in an effort to conserve electricity by having business hours correspond to the hours of natural daylight. 怎么错了？ 这句什么意思啊？
12. Essential a nineteenth-century instrument, the calliope was usually played outdoors and was a part of fairs, holiday gatherings, and other such activities. 怎么改，为什么？ Green peace, an international organization of environmental activists founded b Canadians, uses nonviolent means to protest and block activities it considers environmentally harm. 为什么 it 不对？harm 对？harmfuul? | 
