It is very difficult____ ____ ____ ____ each other as often as before.
下列地点,既位于北半球和西半球,又有极昼、极夜现象的是 ( )
下列哪项是控制酸雨的根本措施( )
班级准备办一期“中国人民志愿军英雄谱”板报,下列可以入选的人物有( )
①董存瑞 ②邱少云 ③雷锋 ④黄继光