1.give off 发出

例句：Osmanthus blossoms give off [exhale] a rich perfume.

桂花发出浓郁的芳香。

2.surgical biopsy 外科活检

例句：Final diagnosis was based on either surgical biopsy or disease progression on extended follow-up or death.

最终的诊断结论是依据外科活检、长期随访期间的疾病进展情况或死亡来决定。

3.volatile chemical 挥发性化学物

例句：Fifth, the ink, daily cleaning the volatile chemical potions, which leads to health workers and environmental pollution.

第五，日常性的墨水清洗所采用的挥发性化学药水，造成对工人健康及环境的污染。

4.back off 后退

例句：The crowd backed off in terror as the police charged.

警察冲上来时，人群因害怕而后退。