Only the word "penguins" should be highlighted:
Not all penguins enjoy penguin cuisine.
Only the first and third occurences of "penguin" should be highlighted:
Penguins are a sight to behold, with their penguin walk and their penguin tuxedo, they are the comic but formal denizens of the Antarctic.
// 1. Should highlight the element #penguin, // but not #penguin_cuisine. });