问题
选择题
Many students listened to the lecture, but I wondered how much work they took________.[ ]
A. out
B. up
C. off
D. in
答案
答案：D
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Many students listened to the lecture, but I wondered how much work they took________.[ ]
A. out
B. up
C. off
D. in
答案：D
鉴定骨的成分：
| 实验一 | 实验二 | ||
| 实验 | 方法 | 用酒精灯火焰烧鱼骨 | 用稀盐酸浸泡鱼骨 |
| 结果 | ______ | ______ | |
| 鉴别 | 方法 | 用解剖针敲击 | 对折弯曲 |
| 结果 | ______ | ______ | |
| 结论 | ______ | ______ | |
（2）骨在稀盐酸中被溶解后，剩余的物质是______，这种物质使骨具有______的特性．