A:衍射条纹间距变窄,衍射现象逐渐消失
B:衍射条纹间距离变宽,衍射现象越加显著
C:衍射条纹间距不变,亮度增加
D:衍射条纹间距不变,亮度减小
关于x的一元二次方程kx2+2x﹣1=0有两个不相等的实数根,则k的取值范围是( )
如图,在平面直角坐标系中,过点M(﹣3,2)分别作x轴、y轴的垂线与反比例函数y=4x的图象交于A、B两点,则四边形MAOB的面积为( )
⑴____ A. teacher B. great C. please D. eat
⑵____ A. school B. good C. book D. football
⑶____ A. cousin B. about C. trousers D. out
⑷____ A. window B. flower C. now D. down
⑸____ A. her B. teacher C. fattier D. flower