It is chemicals that sustain vent life.A．YB．NC．NG

The use of chemicals and fertilizers in farming is meant to increase ______.

A．the quantity of foods

B．the quality of foods

C．either the quantity or the quality of foods

D．the quality as well as the quantity

The new requirements for the active chemicals in a medicine must be labelled ______.

A．at the top of the product container

B．inside the product container

C．inside the cap of the product container

D．at the bottom of the product container

A．By forcing them farming.

B．By affecting the quality of mils.

C．By adding chemicals and pollute the waterways.

D．By affecting the environments they live in.

By saying "they employ chemical warfare" (Line 4, Para. 2), Bruce Ames means "______".

A．plants produce certain chemicals to combat pests and diseases

B．plants absorb useful chemicals to promote their growth

C．farmers use manmade chemicals to dissolve the natural chemicals in plants

D．farmers use chemicals to protect plants against pests and diseases

What is the most frightening aspect of the chemicals in the world？

A．Over 143,000 chemicals have been produced.

B．Chemicals are overused in many areas of our life.

C．The chemicals" effects are not clearly known.

D．Human beings become dependent on chemicals.

According to Laura, the word 'organic' describes ______.

A．a way of farming that is completely free of chemicals

B．a kind of food from which all chemicals have been removed

C．a way of growing things without using artificial chemicals

D．a kind of food that contains natural but not artificial chemicals

Farmers use chemicals and fertilizers in order to ______.

A．improve their working conditions

B．increase the yields of their crops

C．provide their crops with more vitamins and minerals

D．improve the quality of goods grown in commercial farming areas