A faster route through this kind of matching question is to lock the easiest pair first, then use it to knock out wrong options, instead of checking every sentence in order.
Start with sentence 6: "He has seen the ups and downs of life." Here "downs" is a plural thing being seen, a noun, so this is 3-6.
Check every option for 3-6: option A has 3-6, option D has 3-6 too, but option B has 3-8 and option C has 3-7. So B and C drop out right away.
Now compare A and D on just one more pair: option A pairs 2 with 5, option D pairs 2 with 7. Sentence 5 reads "The fire engine came rushing down the hill," where "down" connects the verb to "the hill," which is what a preposition does. So 2-5 is correct, not 2-7.
Rule out option D: since option D needs 2-7 and that is wrong, D cannot be the answer.
That leaves option A as the only survivor, and its remaining pairs, 1-8 (down train, describing a noun, adjective) and 4-7 (Down with the tyrant, a command, verb use), both check out too.
Let's summarize:
downs (a thing) = noun, matches sentence 6
down the hill (linking word) = preposition, matches sentence 5
down train (describes a noun) = adjective, matches sentence 8
Down with the tyrant (command/action) = verb, matches sentence 7
So the full correct set is 1-8, 2-5, 3-6, 4-7, which is option 1.
