I think he will be back_ in an hour _对划线部分提问 __ __ you think he will be back

问题描述:

I think he will be back_ in an hour _对划线部分提问 __ __ you think he will be back

应该是
When do.............

When do

how soon
绝对没问题,这是我经常给学生强调的问题

how long