back

 Mr. Yang is very busy. He _____twelve hours a day. He will call you as soon as he ___ back.

Now that she is out of job, Lucy ___ going back to school，but she hasn’t decided yet.

_______ it is you’ve found, you must give it back to the person it belongs to

He wet to work to make his room neat and put his thing back ______ he wanted them.

背靠背（back-to-back）的专家调查法是指（    ）

背靠背（back-to-back）的专家调查法是指（    ）