Exercise 4: Listen to the dialogue and try to fill in the blanks.

　

       Jim   : Good morning, Prof. Smith.  1   for the book you sent me. It is 2   to my term paper.

    Smith   : 3   it is helpful to you.

       Jim   : Yes, it's indeed a good reference book. I don't know how I shall express   4  to you.

    Smith  : It's  5  .

       Jim  : And I'm 6   for all the help and encouragement (鼓励) you've given to me.  

    Smith  : I'm happy to be 7   . Please don't hesitate (犹豫) to let me know whenever you need me.

       Jim   : I will, Professor Smith. You are 8  .