139.In the United States,there is always ____ flow of people to areas of ____ country where more jobs can be found.

A.a;the

B.the;a

C.the;the

D.a;a

140.Students should be encouraged to use ___ Internet as ____ resource.

A./;a

B./;the

C.the;the

D.the;a

139.答案是A,

a folow of 为固定搭配；the country 特指美国。

140.答案是D，

Internet前面必须加定冠词the；resource资源，可数，此处为泛指。