有时他会倒嚼我们喂给他吃的食物，因为他无法吞咽。Sometimes he regurgitates the food we give him because he cannot swallow.手术后你咀嚼和吞咽都会感到困难。After the operation you may find it difficult to chew and swallow.什么食物都要先嚼碎再吞咽。Always chew food well before...
...existentialist theories.存在主义理论The existentialist thinks it very distressing that God does not exist.存在主义者认为这是非常苦恼的,即上帝不存在.Existentialist points of view cause us to reflect and rationally examine existence and its mean...
化石燃料（如煤和石油）属于有限资源。The fossil fuels (coal and oil) are finite resources.发电站烧的煤产自鲁尔地区。The power stations burn coal from the Ruhr region.酸雨并非简单地由烧煤造成。Acid rain is not straightforwardly attributable to the burning of coal....