硫酸铜溶液中加入过量铁粉，充分反应后过滤，留在滤纸上的物质是 [ ]

A．铁粉和铜粉的混合物

B．铜粉

C．铁粉

D．硫酸亚铁和硫酸铜的混合物

All of us are proud _____ the great changes of our hometown. [ ]

A. for

B. of

C. with

D. about