A：CaCO3在水中溶解度很小，其导电能力很弱，所以CaCO3是弱电解质
B：CaCO3在水中溶解度很小，但溶解的CaCO3全部电离，所以CaCO3是强电解质
C：氯气和氨气的水溶液导电性都很好，所以它们是强电解质
D：水难电离，纯水几乎不导电，水是非电解质
根据短文理解，选择正确答案。
Brave
Type: 3D cartoon Comedy Running time: 95 minutes
Merida, a princess, refused to marry a person that she dislikes. This causes trouble for her family and the whole country. Merida turns to a witch(女巫) for help. In doing so, her family and the country are in danger. Merida must save her family and the country before it is too late. X K b1.Com
The Grey
Type: Action Running time: 117 minutes
The Grey is based on the short story “Ghost Walker” written by Ian Mackenzie Jeffers. It's about a number of oil men who are in trouble in Alaska after a plane crash(空难). They have to fight against grey wolves that threaten（威胁） their lives.
Mirror Mirror
Type: comedy Running time: 106 minutes
You must know the story of Snow White. Would you like to see this story again? Come to see Mirror Mirror. It's a comedy about Snow White. Lily Collins and Julia Roberts are the main actresses in this interesting movie.
Chimpanzee
Type: Documentary Running time: 78 minutes
This movie is directed by Alastair Fothergill and Mark Linfield. It's a 2012 nature documentary film about a young chimpanzee named Oscar. He is alone in the African forests until he is raised by another chimpanzee. The chimpanzee takes care of Oscar like his own child.
①行业千万种，从业者至少都应该有一颗基本的“匠心”。
②如果养此匠心，则会耐得住寂寞，坐得住冷板凳，下得了苦功夫，生出一种宁静致远、潜心于事的定力。
③需要提醒的是：涵养匠心，容不得浮躁，容不得唯利是图，容不得急功近利的“速成”。
④多少粗制滥造、速生速朽的物事告诉我们，急于求成于事无益，急功近利更难立身。
⑤这颗匠心，仅是对规律的尊重，对创造的敬畏，更是一种一丝不苟、追求卓越的精神。
按照波尔理论，氢原子的能级是氢原子处于各个定态时的能量值，它包括氢原子系统的电势能和电子在轨道上运动的动能，当一个氢原子从n=4的能级向低能级跃迁时，下列说法正确的是（ ）
