4. Rule for elongation or reduction of R D All R.D. in the region where K1 and K2 makes an obtuse(acute) angle will increase (reduce) its length after twinning
一、单项选择题(本大题共 10 小题,每小题 1 分,共 10 分) 1-5. D C A C A; 6-10. D A B C A 二、多项选择(本大题共 10 小题,每小题 1.5分,共 15分) 1.ABCD; 2.ABC; 3.ABC; 4.BCD; 5.ABCD 6、ABC 7、ABC 8、ABC 9、ABC 10、AB