Fill in the right prepositions

Don't jam ....... your brakes when it rains because your car may skid.
1. on
2. out
3. in
Why don't you join ...... our panel discussion?
1. out
2. in
3. to
Would you like to take part ..... our game?
1. in
2. to
3. at
The notice warned us to keep ........ the grass.
1. out
2. of
3. off
She used to look down ....... other people because she thought they were inferior.
1. to
2. on
3. in
If you have unknown words you can look them ...... in a dictionary.
1. down
2. in
3. up
I am looking forward ..... hearing from you soon.
1. at
2. in
3. to
I expected a lot of him but he let me ........
1. down
2. up to
3. aside
Look ...., grandpa! The stairs are steep.
1. for
2. in
3. out
Shame ... you to tell these lies!
1. to
2. on
3. in