people's health.

　　4．Para. 4　D．Other methods to keep the soil fertile.

　　1～4　________________

　　答案：1～4　CABD

　　Step 2　True (T) or False (F)．

　　1．Organic farmers prefer using natural waste from animals and chemical fertilizers.(　　)

　　2．Using natural waste makes the soil richer in minerals and so more fertile.(　　)

　　3．Using organic farming methods is to grow good food and to avoid damaging the environment or people's health.(　　)

　　4．Using chemical fertilizers has become very common in farming over the past half century.(　　)

　　5．Chemical fertilizers only kill harmful bacteria and pests.(　　)

　　答案：1～5　FTTTF

　　Step 3　Choose the best answers according to the text.

　　1．From the passage, we can see organic farmers are those who ________.

　　A．grow crops with chemical fertilizers

　　B．grow crops with natural fertilizers

　　C．produce organic fertilizers

　　D．care for the environment

　　2．From the fourth paragraph, we know that ________.

　　A．it's not good to plant grass between crops

　　B．peanuts use the surface of soil

　　C．peas and soybeans should be grown together with corn and wheat

　　D．vegetables that put down deep roots are harmful to the soil

　　3．Farmers ________ so that the soil may not get exhausted.

　　A．grow the same crops year after year

　　B．use natural fertilizers

　　C．change crops every few years

　　D．use chemical fertilizers

　　4．How many ways do the organic farmers have to keep their soil fertile and healthy?

　　A．3.　　　　　　　　　　 B．4.

　　C．5. D．6.

答案：1～4　BBCB