Where are the two speakers?

M: Hey, look! The dolphins are chasing the ball!
F:  Arch’ t they lovely? Thank you so much for inviting me to the Ocean Park. And among all animals, dolphins are my favorite!
M: But don’ t you know that recently scientists find dolphins are nothing but some cruel, tough and rude mammals?
F:  How come? look at their warm and soft eyes; the chubby cheeks and that lovely little voice! I think they are one of the most friendly and gentle animals in the world!
M: Yes. That’ s what everyone says about them. But unfortunately, researchers off the coast of Western Australia have made a shocking discovery; they are breaking the universal animal taboo that bans sexual relations within a tight-knit family group.
F:  You mean that they mate with their family members?
M: Yes. What’ s more, scientists even find instances of dolphin gang rape.
F:  That’ s terrible! I wouldn’t like to hear about things like that!
M: But it’ s the truth. Another question: Do you think dolphins are peace loving?
F:  Why? I think they are.
M: But recent evidence shows males enjoy a good shouting match. Apparently, they are attacking others and trying to damage their hearing, because they’ ve been going head-to-head.
F:  Oh, no. I don’ t think most dolphins enjoy doing this.
M: No. most of them tend to stick together for years, even for life. But scientists warn people when joining a group of dolphins in the water, they should be extremely careful, because it is as dangerous as walking into a fight in a club.