问题
选择题
New technologies have made ____ possible to turn out new products faster and at a lower cost. [ ]
A. that
B. this
C. one
D. it
答案
答案:D
New technologies have made ____ possible to turn out new products faster and at a lower cost. [ ]
A. that
B. this
C. one
D. it
答案:D
比较与归纳是学习化学的重要方法.请你分析下列两表中的数据,找出对应规律.
(1)
1g金属与足量稀盐酸反应 (均生成+2价金属的盐溶液) | Mg | Fe | Zn | ||||||
金属的相对原子质量 | 24 | 56 | 65 | ||||||
产生氧气的质量(g) |
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|
| ||||||
你发现的规律是 | ______ |
气体 | H2 | N2 | O2 | Cl2 |
气体的相对分子质量 | 2 | 28 | 32 | 71 |
标准状况下的气体密度(g/L) | 0.0899 | 1.251 | 1.429 | 3.214 |
你发现的规律是 | ______ |