（）是与活塞构成工作容积的部件。
A.气环
B.活塞环
C.汽缸
参考答案：C
His walkman is different from , and it is more expensive. [ ]
A. him
B. mine
C. my
D. her
A．水的价格便宜
B．水的比热容大
C．水有固、液、气三态
D．水能吸收和放出热量
