A、Because it’s hard to classify all of the varieties of animals. B、Because their methods of biological research are inadequate.

W: Hi, John. How are things going?
M: Oh, hi. Fine. How about you?
W: You can probably tell just by looking at me. I’m really busy. (1)Well, what are you reading?
M: (I)A very interesting article. My biology professor assigned it. I thought 1 would just look it through, but I got really involved in it.(1)It’s about endangered species.
W: That sounds pretty interesting. (2)I’m getting frustrated with the two research papers I’m struggling with.
M: Oh?
W: Besides,(2)they are both due on the same day. It’s unbelievable.
M: That’s tough.
W: I’ll get through it. So what’s this you are reading?
M: Well, it’s basically about the choices conservationists are facing with. You know, these days funding is so hard to come by.
W: Wait a minute. Is the focus on biology or economics?
M: Both.(3)Conservationists don’t have enough funding to save every endangered species in the world, so they have to decide, based on what would be lost if a species became extinct.
W: Can you give me an example of what you mean?
M: (4)Take for instance, two animals, the spotted owl and the tailed toad. The article says the toad is unique. It has no relatives. But there are a lot of varieties of owls.
W: (4)So, if that toad became extinct, we’d lose an important link in the chain of evolution, right?
M: (4)Exactly. But that isn’t so for the owl. So for conservationist, it might be a clear choice of which animal to save.
Questions 1 to 4 are based on the conversation you have just heard.
1. What is the man doing?
2. What problem does the woman have?
3. Why can’t the conservationists save every endangered species?
4. As for these two kinds of endangered species spotted owl and tailed toad, which one will be chosen to be saved according to the conversation?