Please complete the following sentences with the proper forms of the words given.
1.She could not bear to live in a____room.(ventilate)
2. This____ruined his reputation by accepting bribes.(politics)
3.The president has decreed that all males will have to____（list)
4.Every day I really have to battle to get on the bus,it.s always so_____（crowd)
5.My house has a____system that will not be fouled up by large quantities of refuse.(drain)