请从以下两个小题中任选一题作答,若多选,则按第一题计分.
儿童节期间,文具商店搞促销活动,同时购买一个书包和一个文具盒可以打8折优惠,能比标价省13.2元,已知书包标价比文具盒标价的3倍少6元.那么设一个文具盒标价为x元,依据题意列方程得____
①往Na2SiO3溶液中通入CO2产生白色沉淀
②石墨是导体,晶体硅是半导体
③制玻璃过程中发生反应Na2CO3+SiO2 高温__ Na2SiO3+CO2↑
④CH4比SiH4稳定.
I went to see a film with my friend Kitty y .The name of the film was S .It was a a pretty p ,her stepmother(继母)and a handsome prince.We bought the t from the Internet.The film was very i .