expertizer

例句：

1. 1. The doctor is an expert in treating heart disease.
   这位医生是治疗心脏病的专家。
2. 2. She has become an expert in her field of study.
   她已经在她的研究领域成为了专家。
3. 3. They need to hire an expert to fix their broken car.
   他们需要雇佣一位专家来修理他们的坏车。