—Two months ______quite a long time.

　　—Yes, I’m afraid that he will miss lots of his lessons.

A．is

B．are

C．was

D．were

把少量下列物质分别放到水里，充分搅拌，可以得到溶液的是[ ]

A．二氧化锰

B．菜油

C．硝酸铵

D．木炭粉