Fill in the appropriate phrase in each gap.

Behaviour
Humpback whales are famous for their ... and one of the most ... is that of a humpback whale and ... and ... and tail \(this is known as breaching\). Male humpbacks sing songs that last for up to 20 minutes and are different depending on what ocean they are in. Scientists are not ... why they sing, but one thought is that they do it to ... . Humpbacks have been observed interacting with other species, and they have been seen protecting other sea creatures from predators such as sharks and killer whales.