paragraph A

Topic: sick-building syndrome

Main idea: some buildings create their own indoor air pollution

pragraph B

Topic: indoor air pollution

Main idea: the air inside some buildings is full of pollutants

paragraph C

Topic: types of indoor air pollution

Main idea: many products give off chemicals we can't see but breathe in

paragrph D

Topic: how indoor air becomes polluted

Main idea: some products release chemicals into the air and lack of ventilation makes the situation more serious

paragraph E

Topic: solutions to sick-building syndrome

Main idea: experts must determine the cause and workers must remove it

paragraph F

Topic: plants as a solution

Main idea: some plants remove pollutants from the air

paragraph G

Topic: more research is necessary

Main idea: plants may offer an important pollution-control system for the 21st century