问题
选择题
As the popular saying ______, “Laugh and the whole world laugh with you. Cry and you cry alone.”
A．speaks
B．goes
C．tells
D．talks
答案
答案：B
as the saying goes俗话说。
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As the popular saying ______, “Laugh and the whole world laugh with you. Cry and you cry alone.”
A．speaks
B．goes
C．tells
D．talks
答案：B
as the saying goes俗话说。
化学兴趣小组为了测定石灰石中碳酸钙的质量分数（杂质不溶于水，也不与盐酸反应）．测得的数据如下：
| 实验组次 | 1 | 2 | 3 | 4 |
| 样品质量/g | 30 | 20 | 20 | 30 |
| 稀盐酸的质量/g | 50 | 50 | 100 | 100 |
| 产生气体的质量/g | 6.6 | 6.6 | 6.6 | m |
（2）第______组实验恰好完全反应？
（3）该石灰石样品的纯度是多少？