—What should we do for the disabled children in the Children's Home?
—You're supposed to________ a study group to help them.
A:take up
B:fix up
C:set up
D:stay up
关系
甲商品
乙商品
互为替代品
价格上涨,需求量减少
Q1
互补商品
价格下跌,需求量增加
Q2
已知一组数据:68,69,70,66,68,65,64,65,69,62,67,66,65,67,63,65,64,61,65,66共20个,则落在64.5~66.5这一小组的频数是____。
鉴别下列各组物质所选试剂(括号内)不正确的是( )
The plan they are considering improving greatly.