脑出血最常见的病因为()
A.脑动脉炎
B.高血压合并小动脉硬化
C.血液病
D.脑动脉瘤
E.脑血管畸形
参考答案:B
关于“探究平面镜成像的实验”中,请回到下列问题:
(1)实验用玻璃板代替平面镜做实验,目的是:______
(2)同学在玻璃板的前面放一支点燃的蜡烛A,还要在玻璃板的后面放一支没有点燃的蜡烛B,对蜡烛A和B的要求是______,这是为了______.
(3)在寻找蜡烛像的位置时,小明无论怎样调节后面的蜡烛,都不能与蜡烛的像重合,请你推测可能的原因是______.
(4)平面镜中会出现两个几乎重合的像,是因为:______.
(5)如果图1是物体,在平面镜中看到的像是______
Having finished lunch, the case was discussed .
A.they discussed the case
B.they had discussed the case
C.the case was discussed
D.the case had been discussed