A:镜花水月
B:海市蜃楼
C:坐井观天
D:立竿见影
下列光理象中,由光的直线传播形成的是( )
School violence ______ much attention of the whole society and people are calling on the government to make laws against it as early as possible.
从人的性别决定方式看,生男生女取决于( )
地轴倾斜角度的大小可以影响极昼和极夜现象发生的地区范围。( )