一月JJNO187的核对，谢谢

寂寞的自由

187.s, r, t, u are integers. which one has the same standard deviation as s, r, t, u ?
(a) |s|, |r|, |t|, |u|
(b) s+1, r+1, t+1, u+1
(c) 2s+s, 2r+2, 2t+2, 2u+2
(d) s^2+4, r^2+4, t^+4, u^2+4
自由的答案：B

llllll

agree