【多选题】下列属于提高价值的进化趋势的五个直接趋势的是?()
【简答题】水从高处向下流形成的景观叫“跌水”。环保部门采用跌水充氧技术对生活污水进行处理,其方法是:生活污水首先进入沼气池,经过沼气池处理后的污水再用泵提升进入多级跌水池。跌水池分多格串行,内装组合填料,借助生长在填料上的微生物去除有机物。经过跌水池的污水一部分回流入沼气池,另一部分进入水耕型蔬菜池。 问答下列问题: (1)大量生活污水的排放使河水变黑、发臭,其原因是外来干扰超过了生态系统的_______的...
【单选题】In paragraph two, the author thinks that ______.
A.
society should support all mothers no matter where they work—at home or outside it
B.
working mothers are doing less for their children
C.
we should do more research on this problem
D.
working mothers should be proud
【单选题】Why can girls benefit from working mothers?
A.
Because they tend to take their mothers as life models.
B.
Because they are psychologically closer to their mothers.
C.
Because working mothers like to communicate more with girls.
D.
Because they are always trained by their working mother.
【单选题】531. 脉冲的分配常用软件来实现,由并行输出接口输出,经光藕合器隔离后送驱动电路。脉冲分配程序常采用( )实现。
【判断题】秦隶把小篆圆转弧形的笔画变成方折平直的笔画,基本摆脱了古文字象形的特点。