题干
There's little left at home. Go and buy some, dear.
A：carrots
B：potatoes
C：rice
答案(点此获取答案解析）
C
There's little left at home. Go and buy some, dear.
A：carrots
B：potatoes
C：rice
b 
） 
=a 
b 
，那么m，n的值等于（ ）