【简答题】用下图中的仪器和装置填空,或按要求回答问题: A B C D E F G (1)写出图中①、②仪器的名称:① ,② 。 (2)为完成下列实验,请选择所需上述仪器或装置,将其编号填在横线上,并填空回答问题。 ① 实验室制取并收集氧气(使用氯酸钾和二氧化锰)需用 。 ② 实验室制取并收集二氧化碳需用 。证明收集装置中的二氧化碳已充满的方法是 。 ③ 配制50...
【单选题】Quantum mechanics is a branch of physics,it was initially developed to explain atoms.
A.
Quantum mechanics is a branch of physics;it was initially developed to explain atoms.
B.
Quantum mechanics, a branch of physics, was initially developed to explain atoms.
C.
Quantum mechanics is a branch of physics;It was initially developed to explain atoms.
D.
Both A and B are correct.
【简答题】实验室中用下列装置制FeCl 3 ,可供选择的试剂有:①MnO 2 ②NaOH溶液 ③饱和NaCl溶液 ④浓硫酸 ⑤浓盐酸。 (1)按气体流向由左到右排列,各装置的连接顺序为(填写A~E序号) (2)实验开始时先点燃A处酒精灯,点燃B处酒精灯前必须观察到的现象是______________________________。 (3)A装置烧瓶中反应的方程式是________________C中所...
【多选题】A2题型】女31岁,第一胎39周见红,规律宮缩,临产后行灌肠的适应症是
B.
阴道出血,量较多 c.产程顺利,估计1小时内胎儿即可娩 D.胎膜未破,宮颈扩张2cm,先露高位为+1 E.臀先露,胎心好
【简答题】The Foreign Service is a branch of the Department of State.( )
【单选题】The Foreign Service is a branch of the Department of State.
【多选题】材料抗渗性大小与 ( ) 和 ( ) 有关。