a three-level architecture idea的用法和样例：
- A three level LLC resonant converter is proposed by combining three level technique and LLC resonant technique.
- In the scale based approach, a map could be expressed in a three level scale model included spatial object, block and scale view.
- It is a three ring circus to watch that silly dog play.
- He discarded a three,and picked up a Queen.
- A three piece suite has two chairs and a sofa.