Sentence 1: Kia's friends decided to do the Polar Bear Plunge. 
 Sentence 3: Then they braced themselves and stripped to their bikinis 
 Sentence 4:  They plunged into the icy water, shrieking and laughing 
 Sentence 5:  It was freezing, but Kia had a great time! 
 Given Sentence 2: On December 1st, they all met at the lake.