Wearenowlivinginthemodernsociety.Mostoftheenergyweuseforheatinglightingtransportationandmanufacturing(制造业)comesfromfossil(化石)fuels.Thesearecarbon-basedfuelsfromoilcoalandnaturalgas.Whenw

Question

   We are now living in the modern society. Most of the energy we use for heating lighting transportation and manufacturing (制造业) comes from fossil (化石) fuels. These are carbon-based fuels from oil coal and natural gas. When we burn these fuels we release heat which p__ 小题1: ___ the energy.
There are three main disadvantages to using these fuels. Firstly they are causing climate problems because of the G_ 小题2: ___ Effect. When we burn fossil fuels they produce carbon dioxide which causes global warming. Secondly when we have used up all our coal oil and natural gas we will have n__ 小题3: __ left to burn. Thirdly they are not very efficient. The internal combustion engine (内燃机) that we use in most cars trucks and buses for example is only about 14% efficient.
Scientists are working on another fuel—hydrogen. There are a couple of advantages to using hydrogen as a fuel. Firstly because two-thirds of the e__ 小题4: __ surface is water and water is made of hydrogen and oxygen. There is an almost unlimited supply of hydrogen. Secondly burning hydrogen does not cause global warming. Thirdly it is much more efficient than carbon-based fuels.
Unfortunately there are problems with hydrogen at the present time: there is the problem of separating (分离) it from water c_ 小题5: ___ and there is the difficulty of storing it. It can be stored under pressure but high pressure tanks are far from safe. It can also be stored as a liquid but only at extremely low temperatures. It seems likely therefore that there will have to be a completely new technology before hydrogen replaces fossil fuels. S__ 小题6: ___ these problems is an urgent (急迫的) matter. Although China India and Australia have huge amounts of cheap coal and there are still l__ 小题7: ___ oil and gas reserves(储藏量) elsewhere the effects on the planet’s climate will be bad if they are used.

Answer 1

小题1:provides小题2:greenhouse小题3:nothing小题4:earth's小题5:cheaply小题6:Solving小题7:large分 析：本文讲述了我们的矿产资源。我们的矿产资源都是有限的，不可再生的。现在的石油，天然气，因为燃烧...