Fill in each blank with the correct word from the lesson.

1. Disease-causing bacteria like _______ and typhoid bacilli can survive in sewage and infect anyone who drinks contaminated water.
2. The wastewater flows by _______ — sewers are laid at a slight downhill angle — to a sewage treatment plant.
3. Untreated sewage causes diseases like cholera and typhoid, and env_______mental damage through eutrophication.
4. Sewage contains a complex _______ of harmful substances.
5. Heavy metals like lead and mercury from industrial sources accumulate in living _______isms and cause serious health damage.

Choose the best option for each question.

1. What disease can be spread through untreated sewage in drinking water?
   a) Malariab) Cholerac) Dengued) Tuberculosis
2. What is eutrophication?
   a) Sewage treatment processb) Excess nutrients cause algae to bloom and kill aquatic lifec) Filtering heavy metals from waterd) The natural breakdown of sewage
3. What does a sewer system do?
   a) Treats wastewater at homeb) Stores rainwater undergroundc) Collects and transports wastewater to treatment plantsd) Provides clean drinking water

Write T for True or F for False in the brackets.

1. Disease-causing bacteria like cholera and typhoid bacilli can survive in sewage and infect anyone who drinks contaminated water.
2. Disease-causing bacteria like Malaria and typhoid bacilli can survive in sewage and infect anyone who drinks contaminated water.
3. Excess nutrients cause algae to bloom and kill aquatic life is one of the key concepts in the lesson on What Is Sewage?.
4. Sewage treatment process is the main topic of this lesson.

1. In your own words, explain what What Is Sewage? means.
2. List two things you learned from this lesson on What Is Sewage?.