右上3牙体有较大缺损，在制作金属烤瓷全冠的基底冠时。若蜡型厚_爱下问搜题

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问题单项选择题 A1型题

右上3牙体有较大缺损，在制作金属烤瓷全冠的基底冠时。若蜡型厚度均匀一致，容易产生的结果是（）

A.瓷层厚，能较好地恢复瓷层感

B.爆瓷

C.金属底层冠适合性好

D.瓷裂，瓷变形

E.浪费瓷粉

答案

参考答案：D

解析：如基底冠的蜡型厚度一致，则缺损部分由瓷恢复，瓷层过厚会引起瓷裂和变形。

阅读理解

Here are reports of three attacks (攻击). Three swimmers were attacked by sharks (鲨鱼) because they didn't obey (遵守) the safety rules for swimmers.

Rules for swimmers_:
1. Don't swim at night.
2. You are more likely to be attacked in warm water.
3. Sharks are attacking by blood (血). Don't swim with an open cut（划口）.
4. It's best to wear a swimming suit to match(与……相配) your skin colour. Sharks can see colours.
5. If you see a shark, don't be nervous. Try to swim quietly, with even (平稳的) strokes (划水动作).

Report 1_: Colin was swimming with two friends very late at night. He was attacked by a shark and died.
Report 2_: Ann was a very good swimmer. She bought a new bright red swimming suit. She was swimming with some friends when a shark attacked her.
Report 3_: Jack was on holiday in Australia. He cut his foot on the beach. He went swimming the same day and got attacked.
阅读上面的材料，完成下列句子。(每空一词)
小题1:Colin was attacked by a shark and died because he was swimming with two friends very late at ________.
小题2:It’s not a good idea to wear a ________ red swimming suit like Ann, because sharks can see colours.
小题3:You mustn’t go swimming with an open _________.
小题4:If you see a shark, try to swim ________, with even strokes.
小题5:You can be _________ only if（只要） you obey the safety rules for swimmers.

选择题

[2012·宿州质检]下列实验过程中的有关变化与对应的图形相符合的是（）