bacteria ·noun
Definition: very small living things that sometimes cause disease Level: C1
这种感染是由肺部的细菌引起的。
The infection was caused by ___bacteria in the lung.
我们很幸运，在那段时间，天气寒冷，低温阻止了细菌的传播。
We were just lucky that during that period, the weather was cold and low temperatures prevented ___bacteria from spreading.
科学家正在研究如何控制环境中的有害细菌。
Scientists are researching how to control harmful ___bacteria in the environment.