【单选题】What has taken place in the Great Plains grasslands during the last century?
A.
The average annual rainfall has risen and fallen several times
B.
Large parts of the prairie have been converted to agricultural use
C.
Melting glaciers have formed numerous depressions in the soil
D.
Scientists have transformed the region into one large carbon sink
【单选题】关于计算机文件,下列说法不正确的是( )
B.
文件(File)是指存放在外存储器上的一组相关信息的集合
D.
文件中存放的可以是一个程序,也可以是一篇文章、一首乐曲、一幅图画等
【单选题】________ great progress he has made this term ! He feels _______ .
【简答题】What has risen greatly in the U.S. since 1980?A. The number of overweight kids. B. The amount of corn being added to our foods. C. The number of the items in the average supermarket. D. Both A and B.
【单选题】_________ he has made! He is hard-working enough to achieve good marks.
C.
How great progress it is
D.
How great a progress it is