Rosie Huntington-Whiteley showed off her supermodel physique in bikini bottoms as she took part in the ALS Ice Bucket Challenge on Thursday. The British beauty took to Instagram to share a short clip of her being drenched in ice cold water. "I accepted the #ALSIceBucketChallenge and donated at www.alsa.org and I nominate Guy Aroch, Cassandra Grey and Cher Coulter!" she wrote. Sitting on the edge of a fountain, Rosie addresses the camera, announcing that she accepted the challenge from Australian model Abbey Lee Kershaw. The model lets out a high-pitched scream as the bucket is tipped over her head.