A:冰雪融化
B:汽油挥发
C:蜡烛燃烧
D:干冰升华
已知l,m,n是三条不同的直线,α,β是不同的平面,则下列条件中能推出α⊥β的是( )
若二元一次方程组 {x+y=3,3x−5y=4 的解为 {x=a,y=b, 则 a−b= ( )
温度/℃
25
80
230
平衡常数
5×104
2
1.9×10﹣5
下列说法不正确的是( )
– Mum, I've been studying English since 8 o'clock. _____ I go out and play with Tom for a while?– No, I'm afraid not. Besides, it's raining outside now.