Why should we not throw(a) used tea leaves into sink?(b) cooking oil and fats down the drain?

Why should we not throw(a) used tea leaves into sink?(b) cooking oil a

1.	Why should we not throw(a) used tea leaves into sink?(b) cooking oil and fats down the drain?
Answer» (a) Used tea leaves may choke the drain-pipe of the sink. (b) Cooking oil and fats can harden and block the pipes.