a nurse on duty的用法和样例：
- The nurse on duty was fearful that the patient should get worse.
- Yes, the nurse on duty makes two rounds of the wards during the night.
- Because of the absence, through illness, of a senior nurse, the night nurse on duty was junior and new.
- Nurses on duty must wear uniforms.
- Nurses on duty make two rounds of the wards during the night.