A、To keep banana trees growing fast. B、To prevent bananas from going bad. C、To protect the bunches from cold weather. D、To make

W: So how do the trees reproduce then?
M: Well, bananas are normally grown from suckers which spring up around the parent plant, usually just above the plant. They tend to like to grow uphill or at least that’s the common wisdom.
W: So that’s why banana plantations are usually on hillsides, is it?
M: Yes. They grow best like that.
W: That’s interesting!
M: If you plant them in rich soil and give them plenty of water at the beginning of summer, then they should be well advanced by the beginning of winter when growth virtually stops. But in a country like England, they’re hard to grow, although you can grow them in a hothouse.
W: But in Australia, it’s not difficult?
M: No, though even here, the growers put plastic bags around the bunches to keep them warm. If you go up to the banana growing districts, you’ll see all these banana trees with plastic bags on them.
W: But how do they stop the bananas going bad before they reach the shops?
M: Well, the banana bunches are picked well before the fruit is ripe. Once you cut the bunch, the bananas stop growing but they do continue to ripen. The interesting thing is that once one banana ripens, it gives off a gas which then helps all the others to ripen so they pretty much all ripen within a few hours of each other.
W: Amazing! So do we export lots of bananas overseas, to Europe and Asia for instance?
M: Well, oddly enough, no. I believe New Zealand takes a small proportion of the crop but otherwise they’re mostly grown for the domestic market, which is surprising when you think about it because we grow an enormous number of bananas each year.
W: Yes, well thank you for all that information. I’m sure the tutorial paper will go really well. You certainly seem to have done your research on the subject.
M: Let’s hope so.
6. Why are banana tree plantations usually on hillsides?
7. According to Martin, which factor will affect the growth of banana trees most?
8. What is the aim of putting plastic bags around the bunches?
9. How do people keep the bananas fresh before they reach the shops?
10. From the conversation, which country imports bananas from Martin’s country?