问题
选择题
_____ all day at home writing, the novelist went out for a walk in the evening. [ ]
A. Spent
B. Spending
C. Having spent
D. Having been spent
答案
答案：C
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_____ all day at home writing, the novelist went out for a walk in the evening. [ ]
A. Spent
B. Spending
C. Having spent
D. Having been spent
答案：C
区分下列各组物质，选择的试剂或方法不正确的是（ ）
| 物质 | 选用的试剂和方法 | |
| ① | 空气、氧气和氮气 | 燃着的木条 |
| ② | 硬水和软水 | 肥皂水 |
| ③ | 氯化钙溶液和氢氧化钡溶液 | 碳酸钠溶液 |
| ④ | 棉纤维和羊毛纤维 | 抽丝灼烧 |
A．①
B．②
C．③
D．④