A．在同一化合物中，金属元素显正价，所以非金属元素一定显负价
B．MnO2能加快H2O2分解的速率，则MnO2也一定能加快其他物质分解的速率
C．原子核由质子和中子构成，则所有的原子核中都含有质子
D．____．
Hello, boys and girls. I'm Danny. I'm tall. I'm fat. I can draw my teacher. Look, this is my teacher. He's a new teacher. He's Mr Wang. He's tall. He is big. He can play football and swim. He can ride a bicycle, too. Look at the bicycle. It's not red. It's green. It's new. I like his bicycle. Can you ride a bicycle?
①柏林墙的修建 ②越南战争 ③古巴导弹危机 ④朝鲜半岛分裂
①在价值选择的基础上作出正确的价值判断
②充分利用社会提供的客观条件实现人生目标
③人生的真正价值在于对社会的贡献
④把个人的理想追求融入国家和民族的事业中
A点溶液的溶质化学式为____；
