细菌致病性的构成因素包括侵袭力和毒素两大类。下列哪种细菌结构与侵袭力有关
A．荚膜B．芽胞C．外膜脂多糖D．粘肽E．性菌毛
参考答案：A
--- Where are the students ? How could they keep us waiting for so long?
--- They started an hour ago and they____ be here in fifteen minutes, I think.
A．might
B．would
C．should
D．must
逻辑移位指令SHL用于( )。
A．带符号数乘2
B．带符号数除2
C．无符号数乘2
D．无符号数除2
