Most of us have three meals a day .We take food for granted(想当然)。And we don't think about it. 1 experts argue a food crisis(危机)is coming.This crisis is going to make us 2 the way we think about food.

 Food is in great need 3a growing of world population.By 1960,the population was three billion.It doubled to six billion by 1999.By 2050,this planet will need to  4 at least nine billion people.As a result,the food prices get higher and higher.

 So,what can a   5 ,crowed world do?One suggestion is to eat less meat.Meat uses more natural resources(资源)than grains(谷物) .It requires more  6  to produce one pound of meat than to produce one pound of grain. It also requires between 5 and 10 times more water than vegetables. So ,eating less meat will  7  more land for farming,and it will save water.

 To eat less meat,people will need to change their eating habits. That will not be easy. Americans, for example,have 8 loved meat.  In general, They eat twice as much meat as people in other countries.At the same time,in developing countries like China and Brazil,sales of meat have doubled in the last 20 years.   9  will double again by 2050.Growing need of meat wil continue to put pressure on natural resources.

 World  population is increasing,resources are becoming fewer,and food prices are rising.Therefore, we need to rethink what  we eat every day. For meat lovers, we don't  need to give up meat  10 .But we need to eat more grains and less meat.

    A major development to self-driving cars may change the way we will drive in the future. Google, the leading company in self-driving technology, has changed its develop plan. It had driverless cars built by car factories, but now it will start building its own cars.

    Google has started to build some kinds of experimental electric self- driving cars that look like a Smart car or Fiat 500. There is no steering wheel(方向盘), gas pedal or brake. The only things a human passenger controls are a red "e-stop" button (按钮) for fear stops and a start button. The car's only "friendly" face is designed to make it help people accept self-driving technology.

Google workers took part in a long experiment, in which they used self-driving cars for their usual travel to work. No accident happened, but Google's heads realized that depending on a human passenger to drive in an emergency(紧急情况) wouldn't work because they may be reading, working , or sleeping. Now the self-driving car drives by itself if the driver takes his hands off the wheel for over ten seconds.

Google recently announced that its cars had covered 700,000 miles of public roads, and they were now running in busy city streets. People who love self-driving cars say this will improve transport by making roads safer, cutting down accident, and making less pollution.

    Of course, there's no need to look for parking at a crowded shopping mall. Instead, users could let their self-driving cars drop them off to park itself. A mother who took a test ride said that having the car would allow her more time to catch up with her son. The cars could also allow people who might not be able to drive to enjoy the hand-free driving. And drunk driving? Not a problem. It is very likely that by 2020, driverless cars will be common. Do you believe so?

    March 22nd is World Water Day. It started in 1993.It not only makes us think about the importance of water, but also calls on (号召) us to 1and protect water. Today, we're facing terrible water problems. Among them, wastewater problem is especially2.And the subject of World Water Day in 2017 is" wastewater".

    What is wastewater？It is used water. Usually, wastewater comes from homes,3, hospitals and so on. It is produced by different kinds of activities, including washing the machines, taking showers and using the kitchen. The rain also 4wastewater when it is running down the street during a storm. No matter where it comes from, this kind of water is sure to have 5harmful in it.

    6must we treat (处理)wastewater？Wastewater has a big influence on our life. It causes both illness for us and pollution for the environment. We must care for our environment and our own 7.

How can we treat wastewater？Different kinds of wastewater need different ways of treatment. Wastewater 8homes can be reused. Then there will be 9wastewater. Also, factory wastewater has to be cleaned 10it goes back to nature.

    Researcher Robert Engelman from Population Action International says by the year 2025 about 3000 million people may lack water. At least 18 more countries are expected to have serious water problems. The need for water keeps increasing.

    Mr Engelman says the population in these countries that lack water is growing faster than in other parts of the world. The report says lack of water in the future may result in(导致)several problems. It may even increase1problems. Lack of water often means drinking water isn't safe. Mr Engelman says there are problems all over the world because of diseases, Lack of water may also2more international con flint(冲突), Countries may have to compete for water in the future. Some countries, such as Egypt, the Netherlands, Cambodia, now get sixty percent of their fresh water from other countries. And the report says lack of water would affect(影响)the ability of developing to improve their economies. This is3new industries(工业)offer need a large amount of water when they are beginning.

    The Population Action International study gives several solutions4the water problem. One way, it says, is to find ways to use water for more than one purpose.5way is to teach people to be careful and not to waste water. A third way is to use less water of agriculture, The6also says long-term(长期的)ways of dealing with the water problem must include controls on population growth.