Answer:
1. She <em><u>came across</u></em> some interesting information on the internet.
2. I was worrying about the letter, but finally it <em><u>turned up</u></em>.
3. We <u><em>found out</em></u> later that we had been at the same school.
4. Detectives investigated the case and <u><em>looked into</em></u> every detail.
5. I <em><u>worked out</u></em> where the music was coming from.
6. Jane lost her keys and <u><em>looked for</em></u> them throughout the office.
Explanation:
Phrasal verbs are those compound words that usually contain a verb and a particle. And the past simple form of the verb is when the verb is used in the past tense.
Now, the past simple forms of the given phrasal verbs are- work out (worked out), come across (came across), find out (found out), look into (looked into), look for (looked for), and turn up (turned up).
Now, using these past simple form of the phrasal verbs in the correct sentences are as follows-
1. She <u><em>came across</em></u> some interesting information on the internet. This means that she saw or found out some interesting information on the internet.
2. I was worrying about the letter, but finally it<em><u> turned up</u></em>. Here, turned up means to appear, to be found.
3. We <u><em>found out</em></u> later that we had been at the same school. In this sentence, 'found out' means the realization or discovery that they had been in the same school.
4. Detectives investigated the case and <u><em>looked into</em></u> every detail. The phrasal verb "looked into" indicates that the detectives considered every detail in investigating the case.
5. I <u><em>worked out </em></u>where the music was coming from. Here, the speaker reveals he/she discovered where the music was coming from.
6. Jane lost her keys and <u><em>looked for</em></u> them throughout the office. Jane lost her keys so she searched for them all over the office.
