In what way are the underlined words formed in the following sen

In what way are the underlined words formed in the following sentences? 1） He wolfed down his lunch. 2） There is no milk in the fridge, 3） The headmaster is an easy-going man, 4） You have to show your ID before checking in the hotel. 5） I promised to babysit for my neighbor this weekend.
【正确答案】：【答案1】conversion
【题目解析】：题干中wolf这个名词加了过去式的后缀，说明这个是名词转换成动词，用的方法应该是转换法。题干中划线词汇用的截短法构成，完整词形是refrigerator.题干中划线单词由两个单词easy和going组成，用的合成法构成的单词。题干中划线单词是通过截短法构成。题干中划线单词是由babysitter 这个词通过逆生法形成的。