Chemicals in the body our food into useful substance.A. mix upB. deal withC. bring inD. b

问题补充：

Chemicals in the body our food into useful substance.

A. mix up

B. deal with

C. bring in

D. break down

答案：

A. mix up

B. deal with

C. bring in

(答案→)D. break down

解析：短语辨析。mix up混淆； deal with处理；bring in引进，生产； break down分解，失败。句意：我们体内的化学物质把我们的食物分解有用的物质。故选D。