某些不能够或不宜用定期统计表搜集的全面统计资料,一般应采取的方法是()
A、普查
B、重点调查
C、典型调查
D、抽样调查
参考答案:A
如图所示是小明探究怎样用滑动变阻器改变灯泡亮度设计的实验电路图。当开关S闭合时,要使灯泡变亮,滑动变阻器的滑片P应向哪一端移动?
Living near the sea, ___________________.[ ]
A. we enjoy healthy air and beautiful sight
B. healthy air and beautiful sight is what we enjoy
C. it is healthy air and beautiful sight we enjoy
D. so we enjoy healthy air and beautiful sight