细菌的合成代谢产物有（）
A.热原质
B.毒素与侵袭性酶
C.维生素
D.色素
E.细菌素
参考答案：A, B, C, D, E
At present obtaining more land is only possible as _____ result of urbanization, when more farmers leave _____ rural areas to work in the city.
A．a ; the
B．the ; /
C．a ; /
D．the ; the
腹外疝的先天性因素是
A．剧烈咳嗽B．长期便秘C．腹股沟三角区D．手术切口薄弱E．前列腺肥大
