Let me tell you something about sharks. Sharks are among the oldest animals in the world. There are over three hundred and fifty different kinds of sharks in the world. Most sharks are about two meters long and live in the seas.

    A shark can smell something in the water, for example, the blood of animals. That helps them find their food. Sharks mainly eat fish, other sharks and plants in the sea.

    Most sharks bite people by mistake. They think a person is a large sea animal. When the sun goes down or comes up, sharks are looking for food. So at these times people shouldn't go swimming in the sea.

    Today people kill sharks for food and their skin. The number of sharks in the world is dropping fast.

    Lasers（激光） have many uses including improving someone's eyesight, playing DVDs, cutting the diamonds（钻石） and the list goes on and on. Now, there could be a new use for this powerful tool-changing the weather!

    The Swiss scientist Jean Pierre Wolf is working on using laser beams（激光束） to change the weather for the better. He wants to use it to help stop climate（气候） change. Sounds crazy, right? Well, there is already something kind of like it.

    Cloud seeding（云催化） is a way people stop rain from falling. It uses rockets to release chemicals into the atmosphere（大气层）, but it's not known what this might do to the environment. So Professor Wolf wants to find a better way to do this, and a laser is a good choice since the only thing it uses is light, not chemicals. But how would it work? According to CNN, it would make new clouds. The laser would make condensation（冷凝） happen, in other words producing drops of water. And then the water would turn into really small pieces of ice. Then clouds start to be made just naturally.

    Professor Wolf's hope is to help control the weather in places like California that can face both heavy floods and droughts（干旱）.They are also trying to use lasers to control lightning. Using lasers to change the weather has been tested in a lab, and they have been quite successful in some fields. They are still trying to find out how to use it in the real world, but it could be a new way to stop climate change. "Every time you think you have done everything you can with lasers, something new comes up," said Professor Wolf. "It's quite amazing."

Maybe you need to tell bad news to your parents.Maybe you're feeling worried about something.You want to talk with them，but you don't know how to do that.Here are some suggestions （建议） for you.

{#blank#}1{#/blank#}

Cook，eat，play，or just hang out （闲逛） together.This will give you a chance to have a nice talk.

{#blank#}2{#/blank#}

Do you want to tell them something important or ask for help？Do you need their advice？It helps if you're clear about what you want.Put it into words.For example： "I need your advice.Can we talk？"

{#blank#}3{#/blank#}

Are you worried about their reaction （反应）？Are you afraid that they'll be angry？Don't let those feelings stop you.Instead，let your feelings be part of the talk.For example： "I have something to tell you.You might be angry，but I need to tell you."

{#blank#}4{#/blank#}

If you think you might get nervous when it's time to talk，try practicing.It can help you feel more comfortable （舒服的） when you're talking.

{#blank#}5{#/blank#}

Find a time when your parents are happy.You can ask， "Can we talk？Is now a good time？" And then，just get started.

Swifts(雨燕) live mostly in the air. These small birds are among the fastest animals on Earth. In fact, swifts can go two or three days without touching the ground! To get used to life in the sky, swifts use their speed and the saliva（唾液）in their mouths. 

Swifts can fly faster than 100 miles per hour. That's because their wings are like boomerangs (飞行器). This shape of the wings helps them to fly much faster. They can also move one wing faster than the other, which allows them to make sharp turns without slowing down. Making fast, sharp turns helps swifts catching flying bugs to eat. 

The saliva helps swifts catch bugs to feed their young. It is sticky, like glue. Swifts often fly into clouds of bugs such as mosquitoes and open their wide mouths to catch as many insects as they can. The bird collects insects in its mouth gradually and holds the insects in a sticky ball of saliva. One food ball can contain nearly 1, 000 bugs. 

Swifts also use their saliva as glue to build their nests. The birds catch feathers in the air and stick the feathers together to build a strong nest on the side of a building. Swifts' short feet are not good for walking or standing on land for long. But their sharp claws allow them to stick to rocks and walls so they can take a brief rest before returning their lives in the sky. 

Tests can be stressful.You worry that you haven't studied enough. {#blank#}1{#/blank#}You worry that you do know the answer but will still get it wrong on the test.Tests have been stressing people out for thousands of years.{#blank#}2{#/blank#}

During the Tang Dynasty there lived a talented poet named Meng Jiao.who was born to a poor family. Writing poetry was not a good paying job at that time. {#blank#}3{#/blank#} He realized this had to change and decided to take the Ke Ju exams,which were open for anyone.Meng Jiao studied hard for the tests and took them several times.Each time,he failed,but he never gave up.Finally,when he was 46 years old, Meng Jiao passed the test! He was so happy that he put on new clothes and tied on red flowers to celebrate. {#blank#}4{#/blank#}In English,it is"Horseback riding fast through the spring breeze( 微 风 ) ,while seeing all the flowers of Chang'an in one day."

{#blank#}5{#/blank#} It tells of the excited feelings of seeing all of Chang'an City in a day.On that day,he was able to let go of the disappointments of the past.The poem became famous and was passed down through the years.

Next week, I' ll set off on a trip to the mountains with my friends. I' ve made some {#blank#}1{#/blank#} rules by myself. Here I'd like to share them with you.

●Wear proper clothes, strong shoes and thick {#blank#}2{#/blank#} .

●Do not walk too close to the edge of the hill path.

●Do not go off on your own. Keep together.

●Do not drink all your water at the very beginning.

●Always take care when walking on the path.

●Choose {#blank#}3{#/blank#} ways instead of curly ones.

●Help each other to put up tents.

●If I'm lost, just stand where I am and shout for help.

●Keep calm when any sudden danger {#blank#}4{#/blank#} .

I'm so excited about the coming trip that it's difficult for me to {#blank#}5{#/blank#} these days, especially when I think of the exciting rock, fresh air and soft grass.