C. Male elephants of the African Savanna elephants can weigh six tones only when ... 1) they are very old. 2) they have lived half of their life. 3) they are younger than thirty years old. D. Elephant tusks ... 1) grow all the time during their lives. 2) stop growing when elephants are two years old. 3) help elephants only to defend themselves. E. An elephant's skin ... 1) is flat. 2) doesn't protect them from heat. 3) is not thin.