A:Who are you
B:Who is that
C:Who is this
D:Who is he?
设x,y满足约束条件 {2x+3y−3≤02x−3y+3≥0y+3≥0 ,则z=2x+y的最小值是( )
下列不能说明生物适应环境的是( )
gǔ qín
shàn tīng
shàn zāi
____
tài shān
liú shuǐ
zhīyīn