P: Today we are going to learn about a strange animal, the platypus. What can you tell me about the platypus?
S: Nothing, never even heard of it.
P: The platypus has a duck bill and webbed feet and is a unique Australian animal. It and the two species of echidna, an animal that looks a bit like a porcupine, are the only monotremes. You might be wondering what a monotreme is, right?
S: Like the platypus, we have no idea.
P: Simply put, It refers to an egg-laying mammal. The platypus has a lower body temperature than other mammals and legs which extend out, then vertically below it. These features together with its egg-laying are more like that of a lizard than a mammal.
Platypuses, or platypi, are readily identified by their streamlined body, webbed feet, broad tail and characteristic muzzle or bill which is soft and pliable. An adult platypus is from 45 cm to 60 cm in length and may weigh up to 2.7kg. Females are generally smaller than males.
It is deep brown on the back and on the sides of the head, body and upper surfaces of the limbs.
The underside is a golden color although silky grey is not uncommon. They have two layers of fur-a dense waterproof outercoat and a grey woolly underfur to provide much needed insulation.
The fur on the broad flat tail is coarse and bristly.
Why does the professor say this?
A She wants students to answer what a monotreme is.
B She is almost sure that students do not know the term.
C She is not sure whether the class has already covered the term or not.
D She feels that it is not necessary to explain the term.