A non-productive cough does not expel sputum from the respiratory tract.
干咳指不从呼吸道排出痰液的咳嗽。
2
When we exhale we expel air from our lungs.
当我们呼气的时候，肺将空气排出体外。
3
To accomplish this, Baker and van Deursen designed a fast-aging mouse strain that would, upon receiving a drug trigger, expel p16-producing cells from fatty tissues, muscles and eyes.