a yellow-dog contract的用法和样例：
- They saw a yellow dog run out from behind the door.
- He is a yellow dog, and all of us hated him.
- I dislike Tom for he is a yellow dog.
- In spite of the fact you treat him very nice, he is a yellow dog.
- The cat turned chicken the moment Yossarian released him and fled from Humgry Joe ignominiously like a yellow dog.
- He is a yellow dog.