帮忙英文词组区别下

过去常常：Used to always do sthing in the past.

我过去常常很晚睡觉。
I used to always sleep late in the past.

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被用作: Sthing were/was used as sthing.

照片被用作广告
The pictures were used as advertisement.

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习惯于：I am used to doing sthing.

我习惯很快的完成作业。
I'm used to doing homework quickly.

不知道这是不是你想要的？

过去常常: used to (eg. I used to do sth./我过去常常做某事。)

被用作: be used (eg. The cell phone is used as a camera./手机被用
作照相机来用)

习惯于: get used to (eg. Nobody asks why, because we get used to it./
没有人问为什么，因为我们都习惯了。)