缆线综合管廊的连接对象为（）。
A.输送原站-大型用户
B.综合管廊-小型用户
C.输送原站-终端用户
D.输送原站-小型用户
参考答案：C
—Does John serve in the army?
—No, but he________in the army for 8 years.
A．would serve
B．has served
C．is serving
D．served
燃气快速热水器
