你想吃披萨吗？呃-呃，我不饿。

Do you want pizza? ___Nuh-uh, I'm not hungry.

我问他能不能借他的车，他只是摇头说"呃呃"表示拒绝。

When I asked if I could borrow his car, he just shook his head and said "___unh-uh".