测者眼高为9m，物标高程为25m，则物标地理能见距离为（）nmile。
A．6.27
B．10.45
C．16.72
D．17.67
参考答案：C
It is recommended that the project ________ until all the preparations have been made.
A．is not started
B．will not be started
C．not be started
D．is not to be started
图示结构（EI=常数）支座B的水平反力RB等于：（）
A.10kN（→）
B.10kN（←）
C.15kN（→）
D.0
