Organic farming means growing crops ________ fertilizers．

A．

with chemical

B．

without chemical

C．

with

D．

without

The fertilizer that organic farmers prefer is ________．

A．

natural waste from animals

B．

chemical fertilizers

C．

water

D．

pests

Using chemical fertilizers can cause the following problems except that ________．

A．

they affect the soil and water supply badly

B．

they exhaust the soil

C．

they kill both helpful and harmful pests

D．

they make the soil richer

When farmers use ________ they keep the air, soil and water as well as the food supply free from chemicals．

A．

fertilizers

B．

natural waste from animals

C．

chemical fertilizers

D．

chemicals

The main idea of the last paragraph is that organic farmers ________．

A．

keep their soil rich and healthy in three ways

B．

insist on changing crops every two or three years

C．

plant seeds in different layers of the soil

D．

plant grass between crops