Question

Identify the preposition for the sentences in questions

4. The legendary Pony Express rode its way into American history.

5. He rider's trail began at St. Joseph, Missouri.

6. A weary rider would often reach California in 10 days.

7. The Pony Express lasted only 18 months, but it was popular nonetheless.

Identify the conjunction for the sentences in questions

8. Earth rotates on its axis and revolves around the sun.

9. Neptune is an ocean blue color, so it was named for the god of the sea.

Answer 1

Preposition are words that indicate location. Location may be physical or in relation to time.

4. INTO
5. AT
6. IN
7. BUT

Conjunction are words used as joiners. It links words to words; phrases to phrases ; clauses to clauses.

Conjunctions are limited to FANBOYS. 
F- for ; A - and ; N - nor ; B - but ; O - or ; Y - yet ; S - so.

8. AND
9. SO

Answer 2

4. into

5. at

6. in

7. no preposition

Prepositions tell the relation of one noun or pronoun to another. For example, in sentence 5 "at" gives the relation of the trail to the beginning. There is no preposition in sentence 7.

8. and

9. so

Conjunctions join words together. In sentence 8, the conjunction, and, joins Earth's two actions (rotates, revolves). In sentence 9, the conjunction, so, joins the description of Neptune's color to the reason for its name. The word "for" in sentence 9 is being used as a preposition, not a conjunction. Sentence 7 has a conjunction - but. It joins together two complete sentences.