Crabs and their close relatives have 10 legs, arranged in five pairs. Some of their legs are used for walking, while others are used for swimming or defense.
Definition of plunge for English Language Learners. : 1  a sudden fall or jump usually from a high place. : 2  a sudden quick fall in amount, value, etc. : 3  the act of suddenly beginning to be in a particular condition or situation.
Backstroke is a another stroke which exercise almost identical muscle groups as freestyle, with the major difference being that backstroke is swum on your back so therefore your face is out of the water and there is no need to twist your head to breath as in freestyle.