在ARPA中,目标的历史航迹点一般是用来()。
A.判断目标是否有碰撞危险
B.复核避让的目标是否让清
C.估计跟踪的船是否机动
D.核查本船采取的措施是否有效
参考答案:C
Deeply moved by her words, ____________. .
A.tears came to his eyes
B.he could hardly hold back his tears
C.tears could hardly be held back
D.his eyes were filled with tears
各观察值均加(或减)同一数后()
A.均数不变,标准差改变
B.均数改变,标准差不变
C.两者均不变
D.两者均改变
E.以上均不对