集合A={2,4,a3﹣2a2﹣a+7},
由题意得a3﹣2a2﹣a+7=5,
∴a=2,a=1,a=﹣1,
当a=2时,B={1,5,5,25}不合元素的互异性,
当a=1时,B={1,0,5,12}不满足交集是{2,5}
当a=﹣1时,B={1,﹣10,2,4}不满足交集是{2,5}
检验得,均不符合.
实验室配制50g质量分数为15%的氯化钠溶液时,下列某操作对溶质质量分数没有影响的是( )
65+68=____
When seeing the thief stealing something in the street,my uncle seized him by________arm and handed him over to the police in________end.