Here are the words with different sounds in the underlined parts:

1. **C. celebrate** - The underlined "e" in "celebrate" has a different vowel sound compared to the "oo" in "cooker," "ea" in "teacher," and "e" in "pleasure."
2. **A. hour** - The underlined "ou" in "hour" has a different vowel sound compared to the "o" in "horse," "o" in "hobby," and "o" in "hope."
3. **A. laugh** - The underlined "au" in "laugh" has a different sound compared to the "e" in "shelf," "o" in "of," and "e" in "fell."
4. **C. cinema** - The underlined "e" in "cinema" has a different vowel sound compared to the "a" in "candy," "a" in "fantastic," and "o" in "popcorn."
5. **C. Christmas** - The underlined "i" in "Christmas" has a different vowel sound compared to the "a" in "architecture," "o" in "chocolate," and "e" in "mechanic."

So the answers are:
1. C
2. A
3. A
4. C
5. C