KIC is the index of fracture toughness of type I crack. The following statement is correct（）
A. when KⅠ ＜ KⅠC, crack began to expand, brittle fracture
B. when KⅠ ＞ KⅠC, crack extension occurs brittle fracture of instability
C. when KⅠ = KⅠC, extension began to occur
D. when KⅠ = 1/2KⅠC, crack extension
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The following statement about fatigue is true（）
A. The stress of fatigue is higher than the yield strength of static load
B. Obvious plastic deformation can be observed at fatigue fracture
C. Fatigue fracture can be divided into fatigue source, bright area, rough area
D. The occurrence of fatigue fracture is premonitory and is called brittle fracture
What’s true about the fracture is that（）
A. Brittle material fracture fibrous
B. Ductile materials have no obvious plastic deformation before fracture
C. The fracture of the ductile material is crystalline and shiny
D. The fracture of brittle materials is crystalline or porcelain
__ is a measure of how organizations are becoming more heterogeneous in terms of gender, race, and ethnicity（）
A. Globalization
B. Workforce diversity
C. Affirmative action
D. Organizational culture
The core board of the Hongmu round table in the
figure below has natural texture and color. It comes from the intertwined and
natural texture of the old trunk during the growth of trees. In roseThe core board of the Hongmu round table in the
figure below has natural texture and color. It comes from the intertwined and
natural texture of the old trunk during the growth of trees. In rose
A. grimace
B. cattle hair pattern
C. burl
D. golden star
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