题目内容
5. They have to give this machine some oil every month. (对画线部分提问)
do they have to give this machine any oil?
5. How often
练习册系列答案
相关题目
题目内容
5. They have to give this machine some oil every month. (对画线部分提问)
do they have to give this machine any oil?
5. How often