“to kill two birds with one stone”means to ( ) .
A. spend time and moneymaking success
B. do things without conside1ing its results
C. solve both problems with only one move
查看答案
What can you be asked to do to while using Duo lingo? ( ).
A. To the product with others.
B. To pay for the exercises you learn.
C. To describe the image that you see.
对视距加以限制，可以减小的误差影响有：
A. 气泡居中误差
B. 读数误差
C. 视差
D. 球气差
使前后视距相等，可以消除或减弱视准轴与水准管轴不平行的误差的影响。（）
A. 对
B. 错
采取往、返观测，取较大值的成果，可以减小尺垫下沉造成的误差影响。（）
A. 对
B. 错
微信支付 
支付宝支付