【简答题】They want to know if we'd be interested in s____ a tour they want to make to East Asia.
【单选题】They want to know ()to help us.
【单选题】They want to know ______ do it to help us.
【单选题】They want to know ________ do to help us.
【单选题】They want to know ______do to help us.
【单选题】They want to know_ do to help us.