Question

They want to develop a kind of dog-friendly food _________ will help dog owners cool down  their pets.

A．who

B．what

C．which

D．whether

Answer 1

C

考查定语从句的引导词。句意“他们想研制一种对狗有好处的狗粮，这种狗粮会帮助狗的主人安定他们的宠物。”先行词food指物，排除who；what不能引导定语从句；which指物。故选C。