支气管、血管、神经、淋巴管等进入的门户（）
A.肺门
B.肺叶
C.肺段
D.肺泡
E.肺根
参考答案：A
—-______
—Certainly, it is my great pleasure.
A．Can you give me a hand?
B．How are you getting on with your work?
C．What can I do for you?
D．What a nice day!
在ios base类中定义了3个用于文件流定位的枚举常量，下列枚举常量不属于此类的是( )。
A．ios_ase：：beg
B．ios_base：：cur
C．ios_base：：end
D．ios_base：：ate
