甲醇的特点是什么？
参考答案：
无色、透明、有毒、易挥发且能与水无限量混合。
When I was in the countryside, I would go to the river bank ____.
A．each second day
B．every a few days
C．each two days
D．every few days
动物细胞培养的顺序是
①原代培养②传代培养③胰蛋白酶处理组织，形成分散的悬浮细胞 [ ]
A．③①②
B．①②③
C．②①③
D．①③②
ld go to the river bank ____.