直线,AB的往测为213.41m,返测为213.35m,其相对误差为( )。
A.1/3000
B.1/3500
C.1/4000
D.1/5000
参考答案:B
As you can see, the number of cars on our roads _____ rising these days. [ ]
A. was keeping
B. keep
C. keeps
D. were keeping
滴定管调整液面时应使滴管的()充满溶液。
A.底部
B.管内
C.控制流量部分
D.尖嘴部分