a public service broadcast的用法和样例：
- The program is presented by the network as a public service.
- Deputy to the National People's Congress, Peter Wong, says RTHK as a public service broadcaster should serve as a government mouthpiece and refrain from criticizing the administration.
- A motion moved by Hon SIN Chung-kai on public service broadcasting for Hong Kong was passed.
- Among a range of issues, it looks at ITV's public service broadcasting obligations, which the network wants to relax.