Sustainable development is applied to just about everything from energy to clean water and economic growth, and as a result it has become difficult to question either the basic assumptions behind it or the way the concept is put to use. This is especially true in agriculture, where sustainable development is often taken as the measure of progress without a proper appreciation of historical and cultural perspectives. To start with, it is important to remember that the nature of agriculture has changed markedly throughout history, and will continue to do so. Medieval agriculture in northern Europe fed, clothed and sheltered a mainly rural society with a much lower population density than it is today. It had minimal effect on biodiversity, and any pollution it caused was typically localized. In terms of energy use and the nutrients captured in the product it was relatively inefficient. Contrast this with farming since the start of the industrial revolution. Competition from overseas led farmers to specialize and increase yields. Throughout this period food became cheaper, safer and more reliable. However, these changes have also led to habitat loss and to reducing biodiversity. All this means that agriculture in the 21st century will have to be very different from how it was in the 20th. This will require thorough thinking. For example, we need to move away from the idea that traditional practices are certainly more sustainable than new ones. We also need to abandon the notion that agriculture can be "zero impact". The key will be to abandon the rather simple and static measures of sustainability, which centre on the need to maintain production without increasing damage. Instead we need a more dynamic interpretation, one that looks at the pros and cons of all the various way land is used. There are many different ways to measure agricultural performance besides food yield: energy use, environmental costs, water purity, carbon footprint and biodiversity. It is clear, for example, that the carbon of transporting... Specialization and the effort to increase yields have resulted in  _  . A) Localized pollution B) The shrinking of farmland C) the decrease of biodiversity D) competition from overseas
C

It's amazing how we grow from careless kids to responsible teens. What happens in the course that makes us responsible now? It's the seed that we sow in the beginning which grows and becomes a huge tree. As I sit here, silently thinking about my growth, I wonder over some questions which don't have an answer but it's because of such unanswerable situations that life has become a roller coaster ride. As a kid, I used to read a lot of story books. In one particular book, I read a story of a bird. From then on, that has become an integral   part of my life. It described a male bird which takes a lot of pain to build a nest and the female bird takes shelter in it and nourishes the baby. When the bird learns to fly, the whole family flies off to a different place leaving behind the beautiful nest for other birds to grow their family in it. It made me wonder. How could they so easily sacrifice their house built with so much effort? One night, when I was deep in sleep, I got this particular dream. I was walking miles on the endless road, totally isolated but lined with beautiful trees on the either side. Fascinated by the greenery, I marched towards it only to end up deeper and deeper into the greenery. I happened to stop upon seeing something. It was a massive, wonderful house. I fell in love with that amazing part of art. Yeah, it was indeed a piece of art with every nook and corner touched artistically and lovingly. I don't know why I felt that it was done lovingly. Maybe because, things turn out to be beautiful only when we put our love into it -- just like the food prepared by mom which tastes more delicious with her love. I explored the house only to fall more in love with it. There was a sloping roof which matched with the greenery around; the large central open courtyard reminded me of the activities that might have taken place there which felt lively even now when it is completely deserted. The small water body that kept the house cool added to the beauty of the house -- of course, it was all dried up now.... When the writer read the story of the bird, he probably felt   _  . A) upset B) confused C) amazed D) amused
B

Jumping on your bike, even in the city, is becoming increasingly popular--- in London, for example, cycle use has more than doubled in the past ten years. So, which is the best bike for you?     If you're traveling to work, a folding bike such as one of the models here is suitable unless you're cycling more than a couple of miles, in which case it might be uncomfortable . You can take a fold-up on the train and as it goes indoors with you, it's secure .     For longer journeys, a road bike with drop handlebars and narrow tyres is a good choice. Try Specialized, from PS400. Note that the riding position encourages you to look downwards, which can be dangerous.     Mountain bikes are best suited to off-road travel; their fat and strong tyres are good for climbing steep, muddy slopes . Good brands include Trek and Giant, with prices starting at less than PS300.     A hybrid bike (halfway between a mountain bike and a road bike) is a good compromise with more upright riding position and thin, fast tyres. Ridgeback makes great hybrids, from around PS350.     For a classic sit-up-and-beg bike, it's still hard to beat Pashley, which makes its bikes by hand. Expect to pay around PS500.     Once you've picked your bike, sizing is crucial or you may suffer back or neck pain. A famous bike shop will help you choose the right size frame. The height of the seat should be adjusted carefully---again, a good shop will advise. If you only plan to cycle once or twice a month, you can choose a lower-priced bike, but for regular use, paying more means better quality: cheaper bikes need more frequent adjustment of brakes and gears   ---and tend to be heavier, too. Finally, items such as mudguards  aren't always included. The main purpose of this passage is to   _  . A) give advice on how to choose a bike B) advertise some famous bike brands C) encourage people to go to work by bike D) introduce the advantages of different bikes

A