lease怎么写的？ 要加入以下类似条款：

Section 2.18
(The tenant) to be responsible for unblocking or clearing stoppages in any sink, basin, toilet or waste pipe which serve fixtures if they become blocked with the tenant's waste, or as a result of the action's or inactions of the tenant, his invited guests or visitors.

一般说，我的做法是，如果原因不明（老管子），或着搬进来3个月之内，第一次发生是房东修，以后重复发生是他们的。如果发现是他们造成的，直接让他们付。但是lease要先写清楚。