A、Because they can save much money in this way. B、Because the soil is poor in nutrients. C、Because fertilizers can make plants g

Hello, everyone. My name is Birke Baehr. I came here today to talk about what’s wrong with our food system. I used to think that all of our food came from these happy little farms where pigs rolled in mud and cows grazed on grass all day. What I discovered was that this is not true. I began to look into this stuff on the Internet, in books, in documentary films and in my travels with my family. I discovered the dark side of the industrialized food system. First, there’s genetically engineered seeds and organisms. That is when a seed is manipulated in a laboratory to do something not intended by nature—like taking the DNA of a fish and putting it into the DNA of a tomato. The seeds are then planted, then grown. The food they produce has been proven to cause cancer and other problems in lab animals, and people have been eating food produced in this way since the 1990s. And most folks don’t even know they exist.
    Conventional farmers use chemical fertilizers made from fossil fuels that they mix with the dirt to make plants grow. They do this because they’ve stripped the soil from all nutrients from growing the same crop over and over again. Next, more harmful chemicals, like pesticides and herbicides, are sprayed on fruits and vegetables to kill bugs and weeds. When it rains, these chemicals seep into the ground, or run off into our waterways, poisoning our water too. Then they irradiate our food, trying to make it last longer, so it can travel thousands of miles from where it’s grown to the supermarkets.   
    I want you to know that we can all make a difference by making different choices, by buying our food directly from local farmers or our neighbours who we know in real life. Some people say organic or local food is more expensive, but is it real? With all these things I’ve been learning about the food system, it seems to me that we can either pay the farmer, or we can pay the hospital. Now I know definitely which one I would choose.        
    So next time you’re at the grocery store, think local, choose organic, know your farmer and know your food. Thank you.
    Questions 20 to 22 are based on the recording you have just heard.
    20. What do we know about genetically engineered products?      
    21.Why do farmers use chemical fertilizers now?
    22.What prevents some people from choosing organic food?