For these questions, we need to choose the word that best fits the context of each sentence:

**Question 9:** "The children came to class late _____ it rained heavily."

- A. in spite of (This would imply they came early despite the rain, which contradicts the sentence.)
- B. because (This does not fit as it relates to purpose or reason for coming to class, not the rain.)
- C. although (This suggests they came late despite the rain, which fits the sentence.)
- D. because of (This suggests they came late due to the rain, which fits the sentence.)

The correct choice is **D. because of**.

**Question 10:** "We like the food in Hoi An because it is delicious and _____."

- A. affordable (This is a positive attribute often associated with liking food, as it implies good value.)
- B. expensive (Typically, people do not cite expense as a reason for liking food.)
- C. exciting (This could be a reason, but "affordable" is a more common expectation with "delicious.")
- D. fashionable (Fashionable is more about trends and does not align well with liking food's taste and price.)

The correct choice is **A. affordable**.

**Question 11:** "Visiting the old quarters in Hanoi is my _____ experience during my stay here."

- A. typical (This implies it is common and not noteworthy, which does not fit the context of being highlighted.)
- B. believable (This is not relevant to personal experience.)
- C. memorable (This suggests it was significant and noteworthy, fitting the context well.)
- D. forgettable (This contradicts the purpose of highlighting the experience.)

The correct choice is **C. memorable**.