— The summer holiday is on the way. We'll have more freedom.
— . But we should learn to manage ourselves.
A:I'd love to
B:I agree with you
C:I'm afraid I won't
看拼音,写词语。
tǎn kè
máo dùn
bīnɡ xié
pǔ sù
____
nǎo nù
jiāo ào
fǔ tóu
qiān xū
如图,在平面直角坐标系xOy中,过点A(﹣6,0)的直线l1与直线l2:y=2x相交于点B(m,4).
特征量
1
2
3
4
5
6
7
x
98
88
96
91
90
92
y
9.9
8.6
9.5
9.0
9.1
9.2
9.8
附:回归直线方程 y^=bx+a 中斜率和截距的最小二乘法估计公式分别为
b=∑i=1n(xi−x¯)(yi−y¯)∑i=1n(xi−x¯)2 , a=y¯−bx¯ .
如图装置常用来测定空气中氧气的含量.下列对该实验的认识中正确的是( )