我国城镇化面临的主要问题有______。
A.城镇人口高于农村人口
B.城市化水平低于国际水平
C.发展不平衡
D.农民工问题突出
E.缺乏统筹规划
参考答案:B,C,D,E
Mr. Bob, ______ as a manager for many years, found it hard to be an ordinary clerk again.
A.having worked
B.worked
C.to have worked
D.working
一般抽提进料要求非芳含量不低于()。
A、25%
B、30%
C、40%