以正庚醛 、 硫代硫酸钠和溴代正丁烷为原料,合成了正庚醛正丁硫醇缩醛.The heptanal butyl mercaptan was synthesized with heptanal, sodium thiosulfate and 1 bromobutane as raw materials.目的研究以庚醛和原甲酸三乙酯为原料制备庚醛二乙缩醛的工艺条件.Aim Enanthal diethyl acetal is prepared ...
At stake are more than 20,000 jobs in Britain's aerospace sector.英国航天部门2万多人面临失业的危险。At stake is the success or failure of world trade talks.世界贸易谈判正处于成败的重要关头。The life of the sick man is at stake.病人的生命在危急中....
Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better.努力过，失败过，没关系，屡战屡败，屡败屡战，每一次失败都比上一次更好。Sometimes things have to fall apart to make way for better things.有时候要到达谷底，才会慢慢变好。He'd phoned Laura to see if...
Lunar probe has successfully passed the test temperature.月球探测器已经成功通过恒温测试.In the new century, impressive achievements have been scored in manned spaceflight and lunar probe projects.进入新世纪, 我们又在载人航天与探月工程领域取得了令世人瞩目的重大进展....
Check for eyestrain by putting your hand to your forehead a salute.方法是将手放在前额呈敬礼状.To reduce eyestrain, we are going to install anti - glare screens on all of the company's computers.?为了减轻眼疲劳, 我们将在公司的每一台计算机上都安装防辐射屏.Ch...
Our current research topic is photosynthesis.我们现在研究的课题是光合作用。Rates of leaf photosynthesis have little relationship to yield.叶片的光合作用速率与产量的关系不大.In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几...
He radiated self-confidence and optimism.他显得自信乐观。Most of Britain's motorways radiated from London.英国的大多数公路从伦敦向四方延伸.The electric heater radiated warmth.电热器散发出热量....
Keep your eye on these jokers, you never know what they will come up with.留神那些活宝，你永远也不知道他们会想出什么样的主意。Some jokers have let down the back tyres of my car.有人开玩笑把我汽车后轮胎的气放掉了.In many modern packs the jokers are printed in diff...