相关试卷

What does it mean to be green? "Green" is more than just a color. It also means taking special steps to protect the environment. Why green? Plants are green, and without them the Earth wouldn't be such a lovely home for us human beings. What can we do?

Reduce It!

For instance, a shorter shower means you used less water and less fuel since your house uses to run the heater that warmed up the water.

Reuse It!

Sometimes people call ours a "throwaway society". It means that we're a little too willing to throw away old stuff (东西) and buy new stuff. For instance, if your baby brother becomes older and loses interest in his plastic basketball hoop (篮圈), why not give it to another family who has a little kid?

Recycle It!

Recycling has never been easier. Many communities will pick it up right in front of your house and some towns even require it. Recycled goods go to a recycling center, where they can be turned into new cans, bottles, and paper.

Enjoy It!

It's true that rubbish and pollution are problems, but the Earth remains a huge and beautiful place that's ready for you to explore. Go for a hike, visit local nature centers and gardens, and climb up mountains.

But before you travel the globe, take a look at your own backyard. Is there a spot where you could plant a tree or put in a little fruit or vegetable garden?

A. Get out there and get your hands dirty.

B. Here's a four-step guide to being green.

C. Turn off the water when you're brushing your teeth.

D. When you use less of something, you do a good thing for the Earth.

E. You can start locally by visiting the naturally beautiful spots in your city.

F. You can watch with pride as your tree takes root and your garden plants grow.

G. Many times, even if you no longer need something, someone else just might.

Understanding why the giant panda has such noticeable color has been a long-term problem to solve. To find out the answer, Caro and his colleagues looked at photos of pandas and 195 other carnivore (食肉动物) species, including 39 subspecies of bears. Then, they recorded the coloring on each area of those animals' bodies, and compared them with areas of the panda's body. "Compared with the previous studies, the breakthrough in this study was treating each part of the body as an independent area," Caro said.

The research team tried to figure out the purpose of the dark-colored furry areas. After going through many comparisons, the researchers determined that the white parts of the giant panda help it hide in the snow. In contrast, its black arms and legs help it hide in the shadows, they said. The panda's white-and-black coloring didn't appear to be related to temperature regulation. Nor did they find evidence that the dark circles around a panda's eyes helped to make them look cuter.

"This really was a great effort by our team, finding and scoring thousands of images and scoring more than 10 areas per picture from over 20 possible colors," study co-author Ted Stankowich, an assistant professor of biology at California State University, Long Beach, said in the statement. "Sometimes it takes hundreds of hours of hard work to answer the simplest question: Why is the panda black and white?"