By三种用法三句1：2：3：It作形式主语1：Used to2:Be used to do3:Be used to do

1.被,由 The homework was assigned by the teacher.这些家庭作业是老师布置的.2.靠,用,通过 They crossed the river by ferry.他们乘渡船过了河.3.经由;沿 Ellen flew to Chicago by way of Minneapolis.艾伦经由明尼阿波利斯飞往芝加哥
used to表示过去常常做某事.
例句:I used to play football after school.过去我常常在放学后踢球.
be used to do的意思是被用来做某事;be used to doing的意思是习惯于做某事.
be used to 被用来做
used to + do："过去常常"表示过去习惯性的动作或状态,但如今已不存在.
Mother used not to be so forgetful.
Scarf used to take a walk.(过去常常散步)
be used to + doing：对……已感到习惯,或"习惯于",to是介词,后需加名词或动名词.
He is used to a vegetarian diet.
Scarf is used to taking a walk.(现在习惯于散步)

1. It used to belong to me.
2. It used to play with my brother.
3. It used to be a darker shade of red.
1. It is used to do that.
2. It is used to do the housework.
3. It is used t...

By
1.I was asked by Tom.
2.Time goes by.
3.They crossed the river by ferry.
It
It takes my three hours to do my homework.
I uesd to get up late.
The book is used to read.
I am used to seeing him every Monday.

There is a house by the river.
I will be here by 10 o'clock
She come here by bus