1 theme

2 subject

1 question

2 problem

3 issue

4 topic

5 classifier: 个 gè

1 to learn

2 to study

1 habit

2 custom

3 usual practice

4 to be used to

5 classifier: 个 gè

1 to practice

2 field work

3 to intern

4 internship

1 study hard and every day you will improve (idiom)

1 to make a big fuss over a minor issue (idiom)

1 old habits are hard to change (idiom)

1 habit becomes nature (idiom); get used to something and it seems inevitable

2 second nature

1 idiom