PLEASE HELP !!

I need some help with these sentenced, would be so thankful if you guys help me out!

to mumble/ to mutter:

1. Don't.......your words.

2. Are you....threats at me?

3. She was.......away to herself.

4. The student.....and excuse.

now which word fits most suitable in the gaps: A ROAR, ROARS; ROAR; BAWL:

1. His anecdotes sent the audience into........of laughter.

2. Don't........like that: i can hear you.

3. The crowd...........their approval.

4. He........out a curse.

5. They like to listen to the........of the wind and waves.

A PILE; PILES; A STACK; STACKS; A HEAP; HEAPS.

1. The miser gloated over his.......of coins. (stack?)

2. There is a (pile?) of firewood by the fireplace.

3. I see.......of letters on your desk.

4. I have ..... of work to do. (piles?)