A:333 +π
B:233 +2π
C:2 3 +π
D:2 3 +2π
y1
y2
总计
x1
a
b
a+b
x2
c
d
c+d
a+c
b+d
a+b+c+d
A:Our new school is big and nice. There is a gym in our school now.
B:Yes, and there is a big library, too.