第21题: [单项选择]烤瓷合金的热膨胀系数(金α)与烤瓷粉的热膨胀系数(瓷α)的关系是() A. 金α略大于瓷α B. 金α明显大于瓷α C. 金α略小于瓷α D. 金α明显小于瓷α E. 两者无差别 参考答案:A 答案解析:烤瓷合金热膨胀系数必须略大于瓷的热膨胀系数,借此在金瓷冠烧结冷却后金属收缩大,对瓷形成压缩使瓷层形成压应力而非拉应力。
第22题: [单项选择]A. Go to the lab for a while. B. Check on what’s for dinner. C. Go running before they have dinner. D. See if they have plenty of experiments to do. 参考答案:A 答案解析:[听力原文] M: Can you drop by the lab for a minute I have some experiments running that I need to ch