A:生殖能力强
B:体表有角质层
C:口能吞食消化液
D:消化管结构简单
— ________ is the book sale?
— It's next week.
1:1000000的比例尺改写成文字式应是( )
已知点P(x,y)在第四象限,且x2=9,y=5,则P点的坐标是( )
90-3×9=____