温度/℃
10
20
30
40
50
60
溶解度S/g
NH4Cl
33.3
37.2
41.4
45.8
50.4
60.2
Na2SO4
9.6
20.2
40.8
48.4
47.5
47.0
A:乙为NH4Cl
B:t3应介于40℃﹣50℃
C:55℃时,分别将两饱和溶液蒸发等质量的水,得到固体质量甲>乙
D:等质量的甲、乙饱和溶液从t3降温到t1,析出的晶体质量相等
因式分解:(x2+x)2﹣8(x2+x)+12.
已知cosA>12,则锐角∠A的取值范围是( )
— Now I must go _______ I shall be late for the train. — Have a good trip. Goodbye.