I/ Find the word which has a different sound in the part underlined. A. calculator B. compass C. ceiling fan             D. lamp A. arms B. legs C. heads                                 D. chests

1. The word that has a different sound in the part underlined is C. ceiling fan. The underlined part "ceiling" has a 'c' sound (/s/) instead of the hard 'c' sound found in "calculator" and "compass". In "lamp," the 'l' also presents a different pronunciation aspect but not in the same category as the letter sounds.

2. In the second set, the word that has a different sound in the part underlined is D. chests. The 'ch' sound in "chests" is pronounced as /tʃ/, whereas the underlined parts in "arms," "legs," and "heads" all start with vowel sounds or have a different consonant sound.

This shows that "chests" differs phonetically in its initial sound compared to the other words in the group.