— Why don't you ask him for help? You            be good friends.

— We have disagreements and we haven't talked to each other for a long time. [ ]

A. are used to

B. are used as

C. used to

D. are used for

不用任何试剂鉴别下 * * 种物质的溶液：①NaOH ②MgSO₄③Ba(NO₃)₂④Cu(NO₃)₂⑤KNO₃被鉴别出来的正确顺序是（  ）

A．⑤④③②①

B．④③①②⑤

C．④①②③⑤

D．②③①④⑤