Brittle materials have which of the following characteristics()
A. they undergo a lot of permanent deformation before fracturing
B. they tend to have a very ordered atomic structure
C. they respond poorly to tensile forces
D. A and B
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你有6种材料，它们均可分类为后牙复合树脂，但它们各自的配方略有差异。你如何用花费最少、时间最短的试验来确定哪一种材料凝固后毒性最小？
在材料的机械性能测试中，去除外力后尺寸能够完全恢复的最大应力被称为()
A. 屈服极限
B. 强度极限
C. 弹性极限
D. 断裂极限
Chroma is that aspect ofcolor that indicates()
A. degree oftranslucency
B. degree ofsaturation ofthe hue
C. combined effect ofhue and value
D. all ofthe above
测量橡胶材料的硬度，通常用哪个硬度来表征()
A. 布氏硬度(Brinell hardness)
B. 洛氏硬度(Rockwell hardness)
C. 邵氏A(Shore A)硬度
D. 努氏硬度(Knoop hardness)
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