图解西洋妙语之

A knotty problem 棘手问题

Example: I faced the knotty problem of what to have for breakfast

Example: My cat could not only catch mice, but also could[but also](2)play with a person. Once, I was getting tired by a knotty problem(难题)when the cat came. She jumped onto my lap and skipped from one of my knees to the other. Then she jumped back down to the ground and began to play with her own tail, running in a circle.