变差系数
参考答案:
描述随机变量相对于均值离散程度的统计参数,以标准差与均值之比表示。
—What a fine day! Shall we go picnicking?
—________. But we need to be home before six o'clock for the football match.[ ]
A. Have a nice time
B. Pardon me
C. That's great
D. You are right
热辐射不需要通过任何介质将热传播,不受气流、风速、风向的影响。