题型:阅读选择 题类:常考题 难易度:普通
广东省深圳市深圳中学2016-2017学年七年级下学期英语期中考试试卷
C
There is good and bad news about the number of trees on out planet. The good news is that there are seven times more trees for everyone than we thought.
A few years ago, scientists believed that the world bad 400 billion(十亿)trees. However, a new study from Yale University shows that there are around three trillion(万亿)trees. Thatmeans a three followed by 12 zeroes. That means there are about 420 trees for everyone in the world today.
The bad news is that thousands of years ago, the earth had six trillion trees. Humans cut in half the number of trees on the planet. Take Europe for example, it was a large forest thousands of years ago. Now much of it is cities and towns. And another 15 billion trees are lost each year.
Dr. Thomas Crowther is one of the scientists from Yale University. He said the new number of trees from their study would change nothing. " The study only shows we need to do more to protect our forests." He said.
Have you ever stood beside the ocean and stared at the waves (波浪)? The way they move is changing! Nothing is more peaceful than watching the movement of water.
Every ocean has waves. Unless you are lucky enough to live by the sea, though, you probably can't watch the waves very often. How would you like to have your own wave machine? Making one is easy and a lot of fun.
Start with the following things: a glass bottle, water, food colouring, some dish soap, vegetable oil, paint thinner (涂料稀释剂), a cap for the bottle *Note: Use the paint thinner only when your parents agree. Put it away carefully. | |
Step 1: Using the dish soap, wash the bottle carefully. You want your sea to be nice and clean! | |
Step 2: Fill the bottle halfway with clean water. | |
Step 3: Now pm food colouring into the bottle. A few drops will colour the water. You might want to use blue or green. The prettiest colour is actually a mix of blue and green! | |
Step 4: Pour some vegetable oil into your bottle. Pour until the bottle is almost full. Then add some paint thinner until your bottle is full. | |
Step 5: Cap your bottle gently. |
Now that you have made your ocean, put your bottle on its side. Wait a minute. The water win be on the bottom. The oil and paint thinner mixture will be on the top. Now tip (倾斜) the bottle back and forth (反复来回) and watch the waves.
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