Lily thinks young people can learn how to care for others keeping pets.A. atB. inC. byD.

问题补充：

Lily thinks young people can learn how to care for others keeping pets.

A. at

B. in

C. by

D. on

答案：

A. at

B. in

(答案→)C. by

D. on

解析：at在时间空间的一点；in在里面；by通过某种方式，到……为止； on在上面，通过某种媒介。句意：丽丽认为通过养宠物，年轻人能学会如何关心他人。结合语境可知选C。