用be used as 和 be used by 填空

English is used as(被用作为……，被作为……使用) a foreign language in China.

Rubbers are used by(被……使用) the students to correct mistakes.

English is used as a foreign language in China.

Rubbers are used by the students to correct mistakes

1.be used as 被作为。。。来用/被用作
2.be used by sb to do 被某人用来做某事

1 be used as
2 be used by(后面跟人)

the former one is used as , the later one is used by . that is okay .