加快建设创新型科技人才队伍，对推进经济结构的（），建设创新型国家具有重大意义。
A.稳定
B.迅速发展
C.调整
参考答案：C
原煤洗选方法大致分为浮游选煤和（）选煤两种。
A、重力
B、介质
C、密度
D、空气
Working independently, Tina can do a certain job in 12 hours. Working independently, Ann can do the same job in 9 hours. If Tina works independently at the job for 8 hours and then Ann works independently, how many hours will it take Ann to complete the remainder of the job ？（）
A.A
B.B
C.C
D.D
E.E
