A：镁条在空气中燃烧生成的氧化物是MgO，则钠在空气中燃烧生成的氧化物是Na2O
B：HCl的水溶液是强酸，推出HF的水溶液也是强酸
C：CO2与SiO2化学式相似，则CO2与SiO2的物理性质也相似
D：Na、K在周期表中属于同一主族，化学性质相似，Na常温下与水剧烈反应，故K常温下也能与水剧烈反应
The teacher walked into the classroom a smile on his face.
“神九”随火箭加速上升过程中，机械能的变化是（ ）
A student in Fudan University was killed by his roommate just because of small things in daily life. It is important for students to learn how to _________ each other.
