A:30°
B:120°
C:60°
D:150°
____ (happiness) can make us become ill, so we should try our best to be happy.
物 质
X
Y
Z
W
反应前质量(g)
10
2.2
16.2
0.9
反应后质量(g)
a
4.4
8.1
1.8
根据上表信息判断,下列说法中错误的是 ( )