单项选择题
A.σlI=σl1+σl2+σl3;σlII=σl4+σl5 B.σlI=σl1+σl2+σl3σlII=σl4+σl5+σl6 C.σlI=σl1+σl2;σlII=σl3+σl4+σl5 D.σlI=σl1+σl2+σl3+σl4;σlII=σl5
A.90kPa B.70kPa C.94.8kPa D.166.6kPa
A.120kPa B.170kPa C.240kPa D.85kPa