State whether the following statement is true or false. In case the statement is false, write the correct statement.
Where underground sewerage systems and refuse disposal systems are not available, the high cost on-site sanitation system can be adopted.

How are open drains harmful for human health?

Name two inorganic impurities present in sewage.

Animal waste, oil and urea are some of the organic impurities present in sewage. Name two more organic impurities present in sewage.

Name two alternative arrangements for sewage disposal where there is no sewerage system.

A man travelling in a train threw an empty packet of food on the platform. Do you think this is a proper waste disposal method? Elaborate.

Why should we not throw used tea leaves into sink?

Why should we not throw cooking oil and fats down the drain?

Match the Items of Column I with the items of Column II with reference to sewage.