Here's why:
* Spelling: The word "bell" ends with a single "l". This is a common indicator of a long vowel sound in English.
* Pronunciation: The "e" in "bell" makes a sound similar to the "e" in "bee" or "see". This is a long vowel sound.
So, the word "bell" is pronounced with a long "e" sound, making it a long vowel sound.