（）也称自身感染，引起感染的病原体来自病人本身。
参考答案：内源性感染
-What does Jenny __________ for supper?
-Chicken and beef.[ ]
A. eats
B. would like to eat
C. like to eat
D. likes to eat
有以下程序：main(){chara1='M',a2='m';printf("%c\n",(a1,a2));}以下叙述中正确的是______。
A．程序输出大写字母 M
B．程序输出小写字母 m
C．格式说明符不足，编译出错
D．程序运行时产生出错信息
