I. 1. truth

   2. silence

   3. go off

   4. kidding

   5. suddenly

   6. die down

II. 1. heavily

    2. rises

    3. fell

    4. was listening

    5. completely

III. 1. against

     2. got to; realized

     3. was standing; when

     4. without; was waiting

IV.  One possible version:

This morning while I was walking to school with my friend Li Lei, we saw an old beggar who looked cold and hungry under the tree. 

While I was thinking whether to help the old man, my friend Li Lei went to buy some bread and milk from a shop, and gave them to him. The old man said thanks to Li Lei. 

I was moved by what Li Lei did. His kindness touched me a lot. I decided to learn from him and be a kind man.