阅读理解

       My daughter recently asked me what a travel agency does. There is one located on our street and it has just been completely rebuilt. I told her that they helped people book their trips and vacations. “Why haven't we ever been there？” she wanted to know. “Because we do everything ourselves online these days” I explained. “But why do it yourself if other people want to do it for you？” she wondered out loud.

       The answer is that the travel agency makes a little bit of money on each ticket you book through them. If you book your ticket yourself online, you save that money. Saving money sounds great except that when you think about it you typically spend three evenings comparing prices to end up saving $30 on a $300 trip. All those $30 discounts add up of course so I guess we should be happy with that.

       Consider books for a moment. Buying your book at Amazon saves you maybe 30% to 40% on each book. Add to that the convenience of shopping from home and getting the package delivered to your home address. So far so good. Unfortunately, that does mean you spend too much time browsing Amazon. com while you could do something fun instead. Like maybe reading an actual book?

       Then the package arrives and you aren't home and end up having to pick it up at the local post­office. All in all I wonder how much time I end up investing in the whole process. Time sounds free, but to most of us, it is more valuable than money.

       The Internet Economy promised to get rid of the middle—men and we loved it. Somehow, I'm starting to get the feeling that we ourselves ended up doing the work of that middle—men we were so eager to get rid of.

        In any project you can always pick two of these: fast, cheap or good. We seem to have focused a lot on 'cheap' and 'good' but the extra time we need to invest to also keep it 'fast' comes out of our own pockets.

        You can always make more money but you can never make more time.

阅读理解

    Against the assumption that forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.

    This finding suggests that taking steps to prevent northern forest fires to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over next several centuries as a result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.

    This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.

    Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone（臭氧）levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.

    “We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere.” Scientists tracked the change in amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicated, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.

小车从斜坡上滑下来，冲出去的距离与坡度的____、____、____、____等有关。

①情绪影响着我们的观念和行动             ②人与人之间的情绪会相互感染

③我们可以根据自己的需要表达情绪     ④我们要学会合理地调节情绪

①树上挂着红红的柿子。（改为比喻句）

②老师语重心长的话打动了我。（改为“被”字句和“把”字句）

③听了张海迪的故事，我怎么能不感动呢？（改为陈述句）

④你答应了妈妈。你应该遵守诺言。（用关联词合并成一句话）

⑤草地上长着油菜花。（扩句）