Platinum is used to make jewelry.

问题描述:

Platinum is used to make jewelry.
不应该是be used to doing

be used to doing 表示习惯于做某事.
这里考察的是【use sth to do sth 用某物做某事】的被动语态
翻译:铂金一般被用做制作珠宝.
它的主动语态是:People use platinum to make jewelry