Chemicals in the body our food into useful things．
A. break, into
B. break, up
C. break, down
D. break, off
网友回答
A. break, into
B. break, up
(答案→)C. break, down
D. break, off
解析：考查短语辨析。break into 破门而入，break up 解散，break down 分解，break off 中断，句意：身体中的化学物质把我们的食物分解成有用的东西。所以选C。