The provided text includes sections on Conditionals, Suffixes, Obligations, Relative Clauses, and Matching phrasal verbs. What specific homework question does this solution address?

Section One: Grammar

I. Conditionals

1. If you heat water to 100°C, it A) boils.
2. If she studies hard, she B) will pass the exam.
3. If I were rich, I C) would travel around the world.
4. If they had left earlier, they D) would have caught the train yesterday.

II. Suffixes 5. The word 'modernization' contains which suffix? B) -tion. 6. The word 'modern' means 'We need to A) modernize the system.' 7. Choose the word which suffix is -ment? A) agreement. 8. The question "Which word contains which suffix? A) -ise B) -tion C) -ment D) -ate" is incomplete as it does not provide a word to analyze. Therefore, it cannot be answered.

III. Obligations, prohibitions and absence of obligations 9. You A) must wear a seatbelt while driving. 10. You C) mustn't smoke here. It is prohibited. 11. She B) has to finish her homework before going out. 12. You C) don't have to come early if you don't want to.

IV. Relative pronouns & relative clauses 13. The man C) who is talking to my teacher. 14. This is the book B) which I borrowed from the library. 15. The girl C) whose father is a doctor is very kind.

Section Two: Matching 16. look after $\rightarrow$ B) care of 17. take after $\rightarrow$ E) similar 18. come down $\rightarrow$ C) calm 19. come across $\rightarrow$ A) contact suddenly 20. drop out $\rightarrow$ D) leave