相配件的对中性要求高，又需要经常拆卸的静止结合部位，不应采用（）形式。
A.间隙配合
B.过盈配合
C.过渡配合
D.压入配合
参考答案：A, B, D
Young people tend to stay with their family longer on these days for accommodation is expensive but, when they move away to a job or college, there are various options open to them.
A. these days for B. during these days asC. these days as D. within these days for
液体在圆形管路中稳定流动，当体积流量不变管径缩小一倍时，其流速是原流速的（）倍。
A、4倍
B、2倍
C、2.5倍
D、1.75倍
