Acute bronchitis is usually caused by viral infections .

急性支气管炎通常是由病毒感染引起。

Antibiotics do not help people with viral bronchitis .

抗菌素无助于病毒性支气管炎。

The most common of these in western countries are bronchitis and emphysema , which are often caused by smoking .

在西方国家中最为普遍的就是支气管炎和肺气肿，他们常常是由抽烟引起的。

The student health service thought that she might have viral bronchitis , picked up from the children in her class .

学校的学生保健处认为她可能是因为被她班上的学生传染了病毒性支气管炎。

A new report from the blf says there are established scientific links between smoking cannabis and tuberculosis , acute bronchitis and lung cancer .

英国肺脏基金会最新的报告称：吸食大麻和肺结核、急性支气管炎与肺癌之间已经建立起了科学联系。