——Thousands of people come to visit Qinghai Lake every year. ——That's true. It has become our _______.
A:praise
B:prince
C:pride
D:price
直线比射线长。
周长8m的铝合金制成如图所示形状的矩形窗柜,使窗户的透光面积最大,那么这个窗户的最大透光面积是()m
图1 图2