________ the new life in Qingdao，the old man lived happily with his son.

A．Accustomed to　

B．Accustoming

C．Having accustomed to　

D．Having used to

锅炉的保护阀门有（）等。

A.安全阀

B.疏水阀

C.速断阀

D.逆止阀