沉积岩层假整合接触时，上下两套岩层，呈（）接触关系。
A.角度
B.波浪
C.平行
参考答案：C
Many questions________ in today's maths class, and most of them are very difficult. [ ]
A. came up
B. raised
C. rose
D. was come up
多绳摩擦提升机任一根提升钢丝绳的张力同平均张力之差不得大于（）。
A.5％
B.10％
C.15％
D.20％
