In November 1941 Payne was seriously ill with pneumonia.1941年11月,佩恩得了严重的肺炎。The new drug lessens the severity of pneumonia episodes.新药减轻了肺炎发作时的痛苦。She had feared she was going down with pneumonia or bronchitis.她担心会得肺炎或支气管炎...
任何有较强重力的物体都会对其他物体产生引力。Anything with strong gravity attracts other things to it.重返大气层的航天器受到重力的作用。Spacecraft which are re-entering the earth's atmosphere are affected by g forces.由于重力的关系,苹果往下掉.An apple falls down beca...