-Why does Cindy like the music?  

-She likes the music because she can sing along________.  [ ]

A. of              

B. for    

C. with it            

D. with

关于常规阀门的日常维护，下列说法正确的是（）。

A、应保证阀门的各部件灵活好使

B、应保证阀门的填料密封无泄漏

C、应做好阀门的防腐措施

D、应保证阀门各部件灵活好使、且无泄漏，还要做好防腐措施