1,My book hasn't been returned by Mary yet
2,My house is smaller than her house
3,It's difficult to find a job at my age
4,Lan is older than Mai
5,I was sent to school by my parents when i was 6 years old
6,It's easy to get acquainted with the regulation in a new school
7,A motobike is the more expensive than a bycycle
8,It's harmful to smoke a lot
9,this letter isn't written by The principle
10,A birthday cake is being made in the kitchen by Mary