My teacher gave me a number of idioms with gaps to restore and understand it. I figured out some of them but others are unclear to me. Here are idioms with my suppositions:
1. to be gentle as a <sheep?>
2. to talk until the <cows?> come home
3. to be unable to say boo to a <?>
4. to have a <deer?> party
P.S. Above each idiom I have a little picture with an animal.