In order not to have Lily on weight Mom has to cook some food with little fat for her.A.

问题补充：

In order not to have Lily on weight, Mom has to cook some food with little fat for her.

A. put

B. putting

C. to put

D. puts

答案：

(答案→)A. put

B. putting

C. to put

D. puts

解析：考察固定搭配。固定搭配have sb do sth让某人做某事；句意：为了不让Lily发胖，妈妈不得不做了一些脂肪含量很少的食物给她。故A正确。