问题
A number of college students_______ to work in China’s rural (农村的) areas.-Yes, we call them “college-graduate village officials”. Their number is getting_______.They brought new ideas to the less-developed villages.
A:have been encouraged; bigger and bigger
B:has been encouraged; bigger and bigger
C:have encouraged; more and more
D:has encouraging; more and more;
B:has been encouraged; bigger and bigger
C:have encouraged; more and more
D:has encouraging; more and more;
正确答案是：
