devices. And as well as this, air-conditioning systems in large buildings re-circulate the air around the office, carrying germs from workstation to workstation. Research suggests sick building syndrome can be found in roughly 30 per cent of new or refurbished buildings.

But there is some good news for office workers. A lot of companies are making efforts to improve office workplaces. They're installing better lighting and ventilation. They're increasing the number of plants. And they're encouraging employees to take regular breaks from their

computers. So if anyone listening is in an office, take this simple advice: get up, have a stretch, open a window—if you can—and think of ways you can stay healthy in this most unnatural environment.

Passage 2

Karen: Jim, you’ve been a farmer for a long time. Can you explain how

farming methods have changed?

Jim: Well, in the past, most agriculture was small-scale and

labour-intensive, and on the whole worked in harmony with nature. But in the last 50 years, things have changed dramatically, particularly in the industrialized world. Now 41 percent of the world’s farmland is managed intensively. Karen: And what does this mean in practice?

Jim: You see, nowadays, most farms have high productivity which，in one

sense, is a good thing. However, it can mean that vast areas are the farmed with the same crop. Hedgerows are removed and chemical pesticides and fertilizers used. This has a negative effect on the ecosystem and destroys other forms of natural vegetation and local wildlife.

Karen: So do you think we are interfering too much with nature?

Jim: Obviously farmers these days need to produce enough food at a

reasonable price. But I think the problem is that modern agriculture encourages the use of a unlimited numbers of species of each crop. Some traditional varieties of apples or grains, for example, are becoming extinct. The new varieties of seed they sell need pesticides and fertilizers and aren’t as resilient to pests as many tradition varieties. And they don’t always produce higher yields for farmers.

Karen: And how about wild life?

Jim: Well, modern agriculture sometimes kills off wildlife which it also

needs for its own survival. In order to bear fruit, 75 percent of flowering plants need to be pollinated. This is traditionally done by bees, butterflies and birds whose populations are actually declining Honey bees are essential for more than 90 commercially grown crops. Farmers in California, for example, now have to release millions of bees to pollinate their almond trees. Karen: So what in your opinion is the answer?

Jim: Going back to more traditional ways of farming. Small-scales farms

are producing a variety of crops and working with nature. Farmers can leave some land uncultivated to create “wildlife corridors”. This will provide a habitat for a variety of traditional plants as well as for the bees and insects needed to pollinate them. Another solution is planting indigenous， or local species. For example, in Africa researchers are encouraging farmers to plant a local wild species of mango that actually produces fruit in four years. Most cultivated varieties take 12 years. People are also starting seed banks to conserve local varieties of plants for the future.

Karen: And is there anything ordinary people can do to help?

Jim: Well, there are several practical things we can all do that will help,

for example.

Unit 5

? Inside view

Andy: I love Chinese, but is the food around here typical? Janet: Well, it depends (on) what you mean by typical. This is mostly Cantonese food, from the south, except for the roast duck, which is from Beijing. But it's different from the food where I come from, in the northeast. Andy: And which is better? Janet: Er, well, in my opinion, I think ... Oh, look, here he comes. Hi Tony! Tony: Hey, Li Hui, Ni hao. Janet: Ni hao! Tony, this is Andy, my colleague. Tony: Hi. Janet: We were wondering if we could ask you some questions about life in Chinatown. Andy: I don't know if Janet's told you, but we're doing a series of reviews on ethnic restaurants here in London for London Time Off. Tony: OK, I see. Andy: And the thing is, everyone eats Chinese and Indian food, but we want to put a bit of background and history on the website. Are you up for this? Tony: OK, fire away! Andy: What I suggest is, if you've got time, we'll do some filming around here, and then we'll put the research together back at the studio. ... Janet, are you ready with the sound this time? Janet: OK. Andy: Just remember to keep the needle out of the red zone. And don't forget to stop us if there's too much background noise. Janet: OK, thanks. Andy: Tony, you work here in Chinatown. Do you live here as well? Tony: No, in fact, very few Chinese actually live in Chinatown. Andy: And in comparison with Chinatown in, say, San Francisco or Sydney, is it larger or smaller? Tony: I'd say it's much smaller. Really, it's only three or four streets. Andy: And the business here, is it mostly the restaurant trade? Tony: Yes, as well as the supermarkets which stock produce from China. Andy: So where do you call home? Tony: Well, like lots of people, my grandparents came from Hong Kong in the 1950s. But I'm a British-born Chinese so I guess this is home now. Andy: So how long has there been a Chinese community in London? Tony: For 200 years. When the Chinese first came to London, they arrived as sailors so they lived in the East End, by the Docks. Andy: And how did they make their living? Tony: Restaurants mostly, but they were also famous for running laundries. Andy: And why did Chinatown move over here? Tony: At the start of the 20th century some of them moved to the West End, which is the entertainment district, to open Chinese restaurants. And gradually, the Chinese from all over London met friends and did business here. Andy: And does it still feel like a traditional Chinese community? Tony: Oh sure. You saw the Chinese gateway and we celebrate Chinese New Year along with the Chinese all over the world. Andy: Thanks. Tony: You're welcome. Andy: How's it going, Janet? Janet: It's fine, that's about three minutes of material. Andy: OK. Let's wind it up, then. Tony, thank you very much, that was really interesting. Very grateful. Tony: No problem. Now, are you hungry? How about some dimsum and crispy roast duck? Janet: Sounds great! I'm starving. Thanks! Tony: Don't mention it. Let's go back to my restaurant. Andy: Sure, I'm starving too! All this talk about food! Thanks, Tony. Tony: You're welcome. ? Outside view

Part 1

We're taking a walk along this peaceful, quiet beach .Just the place to relax .But out there, at other beaches around the world, that's another story. Let's take a look.

These sea lions fight to defend their territory. During the mating season, these elephant seals show aggression to establish dominance. People fight to defend their territory. In some situations, we’re used to it. We even expect it. When you’re on a crowded street, or trying to get into a crowded bus, other people are going to start shoving. It’s not always pleasant, but