9. How much is the rent per month?
月租金是多少？
還能這樣說：
When is the rent due per month?
How about the rental fee per month?
應用解析：
a month of Sundays 很長的時間；
by the month 按月；
month after month 一月又一月；
month by month 逐月，月月
10. The rent is due no later than the twelfth of the month.
租金在每個月的12號之前付清。
還能這樣說：
You need to pay the rent before twelfth of the month.
The latest date for paying the rent is twelfth of the month.
諺語：
Never too late to mend.
亡羊補牢猶未晚矣。
11. This house is for rent.
此房出租。
還能這樣說：
This house is to be let.
It's a house to let.
12. It's really a bargain.
租金很便宜。
還能這樣說：
It's low rented.
The house was cheap to rent.
應用解析：
bargain on doing sth. 商定做某件事；
bargain over the price 討價還價；
a bad bargain 吃虧的生意