Astronauts work in weightless conditions.宇航员在失重的条件下工作。...weightless silk curtains.轻柔的丝质窗帘Photons have no mass—they are weightless.光子没有质量——它们是无重的。Helen described life in a weightless environment during her period in space...
热有时使皮肤上生剌痛的疹子.Heat sometimes causes a prickly rash on the skin.你找医生看过你的疹子 吗 ?Have you consulted a doctor about your rash?我背上出满了疹子.Rashes have erupted all over my back....
Cataracts is a condition that affects the transparency of the lenses.白内障是一种影响晶状体透明性的疾病。The rotor cataracts water over the top of the machines.回转轮将水从机器顶上注入.In one study, light smokers were found to be more than twice as l...