Sure, let's analyze the pronunciation of the underlined parts in each word to determine which one is pronounced differently from the others.

1. A. laughed B. passed C. suggested D. placed
- A, B, and D have the /t/ sound at the end, while C has the /ɪd/ sound.
- **Answer: C. suggested**

2. A. believed B. prepared C. involved D. liked
- A, B, and C have the /d/ sound at the end, while D has the /t/ sound.
- **Answer: D. liked**

3. A. lifted B. lasted C. happened D. decided
- A, B, and D have the /ɪd/ sound at the end, while C has the /d/ sound.
- **Answer: C. happened**

4. A. collected B. changed C. formed D. viewed
- A has the /ɪd/ sound at the end, while B, C, and D have the /d/ sound.
- **Answer: A. collected**

5. A. walked B. entertained C. reached D. looked
- A, C, and D have the /t/ sound at the end, while B has the /d/ sound.
- **Answer: B. entertained**

6. A. admired B. looked C. missed D. hoped
- A has the /d/ sound at the end, while B, C, and D have the /t/ sound.
- **Answer: A. admired**

So, the answers are:
1. C. suggested
2. D. liked
3. C. happened
4. A. collected
5. B. entertained
6. A. admired