I have two elder brothers, ____ in the army for ten years.

A．the elder of whom served

B．the older having served

C．the older of which served

D．the elder one has served

工作票不准任意涂改，涂改后上面应由（）办理延期手续。

A、签发人或工作许可人

B、总工程师

C、安全处长

D、值长