用be used as 和 be used by 填空

问题描述:

用be used as 和 be used by 填空
English _____ a foreign language in China.
Rubbers _____ the students to correct mistakes.

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.