Complete the sentences with one of the following wordes:endangered,exting,rare.
1 A _________ species is a group of animals or plants with a small number of organisms worldwide,usually fewer than 10,000.
2 An animal is _________ when there are not many of its kind alive and it could soon become _______.
3 There are many _________ species that could soon become ______.
4 Dinosaurs lived on our planet a long time before they became _______ 65 million years ago.