1·Breaking down food, absorbing nutrients, and expelling of waste requires chemical processing, mechanical mixing and rhythmic muscle contractions that move everything on down the line.
分解食物、吸收营养，排出废物，则需化学反应，机械搅拌，肌肉韵动三方协作。
2·Belching or burping is your body's way of expelling excess air from your stomach.
打嗝是身体自胃内排出多余气体的方式。
3·I do not want a routine injection of pitocin after the delivery to aid in expelling the placenta.
我不统一用常规的注射催产素来排出胎盘，我一生完孩子就要尽快开始母乳喂养孩子。
4·The CNS must determine how much to increase breathing rate to adequately supply the body with oxygen, while expelling used up oxygen in the form of carbon dioxide.
中枢神经必须决定呼吸频率提高多少才能给身体提供足够的氧，同时排出耗氧后产生的二氧化碳。