The reason is______he is unable to operate the machine.
问题描述：
The reason is______he is unable to operate the machine.
because why that whether 哪一个解释说明
答
选择 that 这是一个表语从句,然后从句 he is unable to operate the machine 又是一个完整的句子,不缺任何成分,所以用 that 引导,,
补充,答案很容易选择 why ,中式英语