they must promise --- their new pets.A kind to B being kind to C to be kind of D to be kind to

问题描述:

they must promise --- their new pets.A kind to B being kind to C to be kind of D to be kind to

D

D

promise to do sth 承诺做某事
他们必须承诺善待他们的宠物。

百度教育团队【海纳百川团】为您解答

D 涉及两个固定搭配
promise to do
be kind to