把下列句子改为被动语态.1.The students must wear scool clothes at school

1.School clothes must be worn at school by students.
2.She often is seen under the tree by people.
3.Tea was brought to weastern world by people.
4.The light was turned off by someone.
5.I will be asked a question next class by the teacher.
6.A pen is used to write by us.
7.This tool was invented in 1908 by them.
8.Plants have been planted for more than 100 years by the farmers.
9.The bad ban was caught just now by them.
10.Many desks and chairshave were mended by them.
11.A bridge is building now by the workers.

1.the students are weared school clothes at school.
2.

school clothes must be worn at school.
she is often seen under the tree.
tea was brought to western world.
the light was turned off.
I will be asked a question next class.
a pen is...