The Moon is likely to become the industrial hub of the Solar System, supplying the rocket fuels for its ships, easily obtainable from the lunar rocks in the form of liquid oxygen.

hub ^{n. 1. the central part of a wheel 轮轴；轮毂；（车轮的）中心部分}

• More likely, Ford Escort will be hub to hub with Renault or Mercedes, but rarely with bicycles made for two. 
• The mechanic noticed a crack in the hub of the front wheel. ^{技工发现前轮的轮毂有一个裂纹。}
• I greased front and rear hubs and adjusted the brakes. ^{我把前后轮轴都加了润滑油并调试了刹车。}

hub ^{n. 2. the central and most important part of an area, system, activity etc., which all the other parts are connected to = center / centre 中心；（活动的）核心}

• Silicon Valley remains the global hub of the high-tech industry. ^{硅谷依然是全球高科技产业的中心。}
• The elaborate chandelier over this table proclaims it as the hub of the household. ^{这张桌子上精致的枝形吊灯宣告它是家庭的中心。}
• Songdo is a stone's throw from South Korea's Incheon Airport, its main international hub. ^{松岛距韩国主要国际枢纽仁川机场仅一箭之遥。}

obtainable ^{adj. that can be obtained = available 可以获得的}

• Further information is obtainable from the local library. ^{更多信息可从当地图书馆获得。}
• The project was designed to be built using easily obtainable materials like cardboard and tape. ^{该项目旨在利用纸板和胶带等易得材料进行构建。}
• Are his records still obtainable? ^{他的唱片还能买到吗？}
  
• This rare mineral is only obtainable from deep sea mines.^{这种稀有矿物只能从深海矿井中获得。}
• The product is obtainable from any major retailer.^{该产品可从任何主要的零售商处购得。}

lunar ^{adj. 月亮的；月球的}

• The lunar surface is covered with craters and volcanic rock. ^{月球表面布满了环形山和火山岩。}
• It is celebrated on the ninth day of the ninth lunar month. ^{它是在阴历九月初九庆祝的。}

in the form / shape of... ^{以…的形式}

• … but a medicine that had worked so well in one form of illness would surely be of equal benefit in another, … 
• Convinced of the importance of education, modern states 'invest' in institutions of learning to get back 'interest' in the form of a large group of enlightened young men and women who are potential leaders. 
• … they have not received adequate treatment unless they are able to carry home with them some tangible remedy in the shape of a bottle of medicine, a box of pills, or a small jar of ointment, … 
• There is no superior 'they' in the shape of managements and hotel hierarchies to darken his holiday days.
• The payment was made in the form of a bank transfer.^{付款是以银行转账的形式完成的。}
• The aid was provided in the form of food and medical supplies.^{援助是以食品和医疗用品的形式提供的。}

The reason lies in its gravity.

lie ^{v. (of abstract things) exist or be found（抽象事物）存在}

• He must decide where his future lies. 
• The hardest part of the competition still lies ahead of us.

lie in... ^{在于/取决于(主语通常为抽象名词)}

• The problem lies in deciding when to intervene. 
• The difficulty lies in knowing what to do next. 
• The cure for stress lies in learning to relax. 
• The key to a solution of that problem lay in an everyday observation. 
• The solution to the problem lies in finding a compromise.^{解决问题的办法在于找到一个折衷方案。}
• His main strength lies in his attention to detail.^{他的主要优势在于他对细节的关注。}

Because the Moon has only an eightieth of the Earth's mass, it requires 97 per cent ^(97%) less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200 mile-journey from Earth's surface into orbit!

an / one eightieth ^{八十分之一}

• The probability of winning the small prize is one eightieth. ^{获得小奖的概率是八十分之一。}

(Br. E.) per cent / (Am. E.) percent ^百分比%

• How about ten-percent less? 
• The output of cars in the U.S last year was 24 per cent less than in 1973. 
• A Harris poll shows that women have 25 percent less leisure time than men do. 

A car with a natural gas-powered internal-combustion engine emits 87 per cent less nitrogen oxide, 70 per cent less carbon monoxide and 25 per cent less carbon dioxide than a car with an engine that uses petrol, according to research by the Honda Motor Co.  ^阅读真题

• The survey of 7,500 people found multi-sneaker buyers were 50 percent more likely to be very assertive and 47 percent more likely to be spontaneous. 
• Women with fuller lips are 28 per cent more likely to be seen as a fun date than marriage material, while their thin-lipped rivals were 57 per cent more likely to have long relationships, the Leicester University study found. 

The idea of colonising Mars ― a world 160 times more distant than the Moon ― will move decisively from the second phase to the third, … ^总结

it ... less / more ... to ... than ... ^句子骨架

• It costs 60 per cent less money to travel from Beijing to Shanghai by train than by plane. ^{从北京到上海坐火车比坐飞机要少花60%的钱。}
• It is less expensive to repair the old car than to buy a new one. ^{维修旧车比买新车更省钱。}

in orbit ^{在轨道上（运行）}

• Space stations are designed to remain in orbit for years. 
• Once in space, the spacecraft will go into orbit around the Earth.
• The International Space Station has been in orbit around the Earth since 1998. ^{国际空间站自1998年以来一直绕地球轨道运行。}