a consultant in obstetrics的用法和样例：
- He has a consultancy in Harley Street.
他在哈利街当顾问 (医师) 。
- A physician who specializes in obstetrics.
- We interviewed Jane Collard, a consultant in stress management.
- Masaaki Imai (born 1930) is a consultant in the field of quality management.
- I think we should bring in a consultant.