A:No garden is without weed
B:Every little makes a nickel
C:Time waits for no ma
D:The onlooker sees the game best
先化简,再求值:
4xy﹣(x2+5xy﹣y2)﹣(x2+3xy﹣2y2),其中x=- 14 ,y=- 12 .
下列关于“显微镜结构及观察植物细胞的步骤(如图)”的叙述,错误的是( )