问题
选择题
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
答案
答案：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。