问题详情

Laser-doppler radar is especiallyvaluable in space missions because__________．
A.it can measure themovement of a spaceship less accurately than a microwave radar
B.it is a new system ofradar
C.it provides precisemeasures of the velocity of space vehicles
D.it is onethousand times more precise than microwave radar请帮忙给出正确答案和分析，谢谢！