在手术前，医生给他开了些镇静剂来缓解紧张情绪。

The doctor gave him some ___tranquillizers before the surgery to calm his nerves.

兽医给那只暴躁的狗注射了镇静剂以便进行检查。

The vet gave the aggressive dog some ___tranquillizers to calm it down for the examination.