Explanation about: "Used to"

I made the following task in order to practice my self alone in english grammar, i found the answers by what sounds "right" but i am interesting if it is possible some one to provide me the grammar explanation for each answer in order to understand the grammar background of each answer.



1)When Bill worked in the city, he___ travel there by train every day.

A. used to

B. got used to

C. was used to

D. had

Correct Answer: A. used to



2)Mary soon _____ living in the country.

A. got used to

B. was used to

C. used to

D. been used to

Correct Answer: A. got used to



3)When we were kids, we________climb the trees near our house.

A. were used to

B. are used to

C. would

D. used

Correct Answer: D. used



4)“Don’t you hate starting work at .m. ?”

“Not really. I am used to _______up early.”



A. get

B. be getting

C. got

D. getting

Correct Answer: D. getting