They don't have to their school uniforms. [ ]
A. dress
B. have on
C. put on
D. wear
答案:D
如图所示的电路,闭合开关S,滑动变阻器滑片P向 左移动,下列结论正确的是( )
A.电流表读数变小
B.小灯泡L变亮
C.电容器C上电荷量增加
D.电压表读数变小
与新生儿肺透明膜病相符的是()
A.一般出生时即发生呼吸困难
B.病重者发生呼吸衰竭
C.病死率低
D.多见于足月儿
E.一般于生后12小时以上发病