A:an=1
B:an=-1n+12
C:an=2-sinnπ2
D:an=-1n-1+32
维护我们的自尊,不应该做的是( )
My father, Mr. White, often __________ at six twenty in the morning.
小肠上皮细胞跨膜运输葡萄糖的过程如图所示,判断下列说法正确的是( )