A:He is going to go for a summer holiday.
B:He is fed up with school work or homework.
C:There is no holiday without school work or homework.
为解决漫画《谣言》中的问题,我们公民应( )
据报道,科学家发明了一种“月球制氧机”,这种“月球制氧机”可利用聚焦太阳能产生的高温加热月球土壤,制得氧气.据此可推断月球土壤中一定含有( )
构成氧气的微粒是 ( )