1 clear

2 distinct

3 to understand thoroughly

4 to be clear about

1 pain

2 suffering

3 painful

4 classifier: 个 gè

1 bitter

2 hardship

3 pain

4 to suffer

5 to bring suffering to

6 painstakingly

1 exhausting

2 hard

3 tough

4 arduous

5 to work hard

6 to go to a lot of trouble

7 hardship(s)

1 why bother?

2 is it worth the trouble?

1 to be very clear about sth (idiom)

1 unable to bear the pain (idiom)

1 lit. the pain of being hanged upside down (idiom); fig. extremely critical situation

2 dire straits

1 to have suffered all kinds of hardships (idiom)

1 to consider from all angles (idiom); to think hard

2 to rack one's brains