问题
选择题
She often _____ big plans that never happen. [ ]
A. gets
B. makes
C. does
D. calls
答案
答案:B
She often _____ big plans that never happen. [ ]
A. gets
B. makes
C. does
D. calls
答案:B
在潜水艇中可用过氧化钠作为供氧剂.请选用适当的化学试剂和实验用品,用图中的实验装置进行实验,证明过氧化钠可用于制取氧气.
(1)A是用CaCO3制取CO2的装置.写出A中发生反应的化学方程式:______.
(2)按要求填写表中空格:
仪器编号 | 盛放的试剂 | 加入该试剂的目的 |
B | 饱和NaHCO3溶液 | |
C | ||
D | 吸收未反应的CO2气体 |