1．(2018·全国卷Ⅰ)Last winter when I went there again, they had a big separate house to raise dozens of chicken.
解析：chicken→chickens 短语dozens of“许多”，后面接可数名词复数，此处应用chicken的复数形式。
2．(2018·全国卷Ⅱ)After supper, we would play card games of all sort in the sitting room.
解析：sort→sorts all 修饰可数名词sort，应用其复数形式sorts。
3．(2018·全国卷Ⅲ)At that moment, I remembered that my father once said, “The classroom is a place for learning and that includes learning from textbooks, and mistake as well.”
解析：mistake→mistakes 根据语境可知，此处表示“从课本和错误中学习”，mistake是可数名词，错误不止一个，因此用复数形式。
