They have always treated us with open hands and we must be generous . A. in returnB. in ad

网友回答

(答案→)A. in return
B. in addition
C. in vain
D. in case
解析：in return意为“反过来”；in addition意为“而且”；in vain意为“徒劳地”；in case意为“万一”。根据句意“他们一向慷慨地待我们，所以我们反过来也得对他们大方一些”可知，答案为A。