下列有关如图甲、乙两点地理位置的叙述,正确的是( )
A:乙位于东半球的热带
B:甲地位于乙地的东北方向
C:甲位于30°E,20°N和温带
D:乙地位于甲地的东北方向
——Though radio and television are ____ popular in the world today, I think the TV is ____ useful.——Of course, on TV we can see and hear what is going on home and abroad.
人体中二氧化碳浓度最高的地方是( )
化学实验里,老师给学生准备了如图几种实验装置.