练习题考试资料

Until the 1980s, the American homeless population comprised mainly older males. Today, homelessness strikes much younger part of society. In fact, a 25-city survey by the U. S. Conference of Mayors in...

Cancer is feared by everyone. And this fear is reaching epidemic(流行性) proportions. Not the disease itself — there is no such thing as a cancer epidemic. Except for lung cancer, mostly caus...

Until the 1980s, the American homeless population comprised mainly older males. Today, homelessness strikes much younger part of society. In fact, a 25-city survey by the U. S. Conference of Mayors in...

Our quarrel with efficiency is not that it gets things done, but that it is a thief of time when it leaves us no leisure to enjoy ourselves, and that it strains our nerves when we try to get things do...

Now let us look at how we read. When we read a printed text, our eyes move across a page in short, jerky movement. We recognize words usually when our eyes are still when they fixate. Each time they f...

Baekeland and Hartmann report that the short sleepers” had been more or less average in their sleep needs until the men were in their teens. But at about age 15 or so, the men voluntarily began ...

Does a bee know what is going on in its mind when it navigates its way to 11 food sources and back to the hive, using polarized sunlight and the tiny magnet it carries as a navigational aid? Or is the...

weather map is an important tool for geographers. A succession of three or four maps presents a continuous picture of weather changes. Weather forecasters are able to determine the speed of air masses...

Some houses are designed to be smart. Others have smart designs. An example of the second type of house won an Award of Excellence from the American Institute of Architects.Located on the shore of Sul...

When families gather for Christmas dinner, some will stick to formal traditions dating back to Grandma’s generation. Their tables will be set with the good dishes and silver, and the dress code ...