Ⅳ. Complete the conversation with proper sentences in the box there is one extra option.
Andy:Hey, Mike! Have you ever heard of the Crop Circle?

Mike:Yes, it's very strange. I'm curious about the possible reasons.
Andy:1.
Mike:That's very unlikely. I don't think there's any aliens* in our life. Why have we never met one before?
Andy:Maybe they are created by nature. 2. You know, storms are common in places with the amazing circles.
Mike:3. It's impossible that storms can make shapes like them. The only thing a storm can do is to make the crops messy.
Andy:You're right. 4.
Mike:I believe it's possible that some people made them on purpose. It's just a prank*!
Andy:5.
Mike:Great idea!
A. That's not the reason.
B. Perhaps it's built by aliens.
C. I have been to the Crop Circle.
D. The storm could be the main reason.
E. Then what do you think the reason is?
F. Maybe we can discuss that with our science teacher.
Challenge yourself
6*. Complete the conversation and practise it with your partner.
A:Hey! Have you ever heard of (1)?
B:Yes, it's very strange. I'm curious about the possible reasons.
A:Perhaps it's because (2).
B:That's very unlikely. (3).
A:Maybe (4).
B:It's impossible that (5).
A:You're right. What could be the reason?
B:I believe that (6).
A:Let's find out scientific explanations on the Internet.
B:Great idea!

Ⅳ. 1-5. BDAEF
7*. One possible version:
A: Hey! Have you ever heard of Bigfoot?
B: Yes, it's very strange. I'm curious about the possible reasons.
A: Perhaps it's because it's a kind of alien from another planet.
B: That's very unlikely. We have never seen any UFOs there.
A: Maybe it's a giant animal living in the forest.
B: It's impossible that such a large animal can hide for so long without being caught.
A: You're right. What could be the reason?
B: I believe that it is just a person wearing a pair of special shoes to play a joke.
A: Let's find out scientific explanations on the Internet.
B: Great idea!