问题
选择题
Ten years ago the population of our village was _____that of theirs. [ ]
A. as twice large as
B. twice as large as
C. twice as much as
D. as twice much as
答案
答案：B
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Ten years ago the population of our village was _____that of theirs. [ ]
A. as twice large as
B. twice as large as
C. twice as much as
D. as twice much as
答案：B
就有关物质的分离回答下列问题：
（1）现有一瓶A和B的混合液，已知它们的性质如下表。
| 物质 | 熔点/℃ | 沸点/℃ | 密度/g·cm-3 | 溶解性 |
| A | －11．5 | 198 | 1．11 | A、B互溶，且均易溶于水 |
| B | 17．9 | 290 | 1．26 |
据此分析，将A和B相互分离的常用方法是： 。
（2）在分液漏斗中用一种有机溶剂提取水溶液里的某物质时，静置分层后，如果不知道哪一层液体是“水层”，试设计一种简便的判断方法: 。