KEY FULL — Listening 7 Homework (đáp án + giải thích)

Good afternoon, everyone.

Well, with some of you about to go out on field work, it's timely that in this afternoon's session, I'll be sharing some ideas about the reasons why groups of whales and dolphins sometimes swim ashore from the sea right onto the beach and, most often, die in what are known as 'mass strandings'.

Unfortunately, this type of event is a frequent occurrence in some of the locations that you'll be traveling to, where sometimes the tide goes out suddenly, confusing the animals.

However, there are many other theories about the causes of mass strandings.

The first is that the behavior is linked to parasites.

It's often found that stranded animals were infested with large numbers of parasites.

For instance, a type of worm is commonly found in the ears of dead whales.

Since marine animals rely heavily on their hearing to navigate, this type of infestation has the potential to be very harmful.

Another theory is related to toxins or poisons.

These have also been found to contribute to the death of many marine animals.

Many toxins, as I'm sure you're aware, originate from plants or animals.

The whale ingests these toxins in its normal feeding behavior, but whether these poisons directly or indirectly lead to stranding and death seems to depend on the toxin involved.

In 1988, for example, fourteen humpback whales examined after stranding along the beaches of Cape Cod were found to have been poisoned after eating tuna that contained saxitoxin, the same toxin that can be fatal in humans.

Alternatively, it has also been suggested that some animals strand accidentally by following their prey ashore in the confusion of the chase.

In 1995, David Thurston monitored pilot whales that beached after following squid ashore.

However, this idea does not seem to hold true for the majority of mass strandings because examination of the animals' stomach contents reveals that most had not been feeding as they stranded.

There are also some new theories that link strandings to humans.

A growing concern is that loud noises in the ocean cause strandings.

Noises such as those caused by military exercises are of particular concern and have been pinpointed as the cause of some strandings of late.

One of these, a mass stranding of whales in 2000 in the Bahamas, coincided closely with experiments using a new submarine detection system.

There were several factors that made this stranding stand out as different from previous strandings.

This led researchers to look for a new cause.

For one, all the stranded animals were healthy.

In addition, the animals were spread out along 38 kilometers of coast, whereas it's more common for the animals to be found in a group when mass strandings occur.

A final theory is related to group behavior and suggests that sea mammals cannot distinguish between sick and healthy leaders and will follow sick leaders, even to an inevitable death.

This is a particularly interesting theory since the whales that are thought to be most social—the toothed whales—are the group that strand the most frequently.

The theory is also supported by evidence from a dolphin stranding in 1994.

Examination of the dead animals revealed that apart from the leader, all the others had been healthy at the time of their death.

Without one consistent theory, however, it is very hard for us to do anything about this phenomenon except to assist animals where and when we can.

Stranding networks have been established around the world to aid in rescuing animals and collecting samples from those that could not be helped.

I recommend John Connor's "Marine Mammals Ashore" as an excellent starting point if you're interested in finding out more about these networks or establishing one yourself.

Good morning, everyone.

Now, whether you're going to university to study business or some other subject, many of you will eventually end up working for a company of some kind.

Now, when you first start working somewhere, you will realize that the organization you've joined has certain characteristics.

And we often refer to these social characteristics as the culture of the organization — this includes its unwritten ideas, beliefs, values, and things like that.

One well-known writer has classified company cultures by identifying four major types.

The first type is called the Power Culture, and it's usually found in small organizations.

It's the type of culture that needs a central source of power to be effective, and because control is in the hands of just one or two people, there aren't many rules or procedures.

Another characteristic is that communication usually takes the form of conversations rather than, say, formal meetings or written memos.

Now, one of the benefits of this culture is that the organization has the ability to act quickly, so it responds well to threat or danger on the one hand, and opportunity on the other.

But on the negative side, this type of organization doesn't always act effectively because it depends too much on one or two people at the top, and when these people make poor decisions, there's no one else who can influence them.

And the kind of person who does well in this type of business culture is one who is happy to take risks, and for whom job security is a low priority.

The next type is known as Role Culture — that's R-O-L-E, not R-O-double L, by the way, and this type is usually found in large companies, which have lots of different levels in them.

These organizations usually have separate departments that specialize in things like finance, or sales, or maintenance, or whatever.

Each one is coordinated at the top by a small group of senior managers, and typically everyone's job is controlled by sets of rules and procedures — for example, there are specific job descriptions, rules for discipline, and so on.

What are the benefits of this kind of culture?

Well, firstly, because it's found in large organizations, its fixed costs, or overheads as they're known, are low in relation to its output, or what it produces.

In other words, it can achieve economies of scale.

And secondly, it is particularly successful in business markets where technical expertise is important.

On the other hand, this culture is often very slow to recognize the need for change and even slower to react.

What kind of person does this type of culture suit?

Well, it suits employees who value security and who don't particularly want to have responsibility.

MOVING ON NOW TO Task Cultures — this type is found in organizations that are project-ORIENTED.

You usually find it where the market for the company's product is extremely competitive or where the products themselves have a short lifespan.

Usually, top management delegates the projects, the people, and other resources.

And once these have been allocated, little day-TO-DAY CONTROL is exercised from the top because this would seem like 'breaking the rules'.

Now, one of the major benefits of this culture is that it's flexible.

But it does have some major disadvantages too.

For instance, it can't produce economies of scale or great depth of expertise.

People who like working in groups or teams prefer this type of culture.

And finally, the fourth category is called the Person Culture...

Good morning.

In the last few lectures, I've been talking about the history of domestic building construction.

But today, I want to begin looking at some contemporary, experimental designs for housing.

So, I'm going to start with a house which is constructed more or less under the ground.

And one of the interesting things about this project is that the owners — both professionals but not architects — wanted to be closely involved, so they decided to manage the project themselves.

Their chief aim was to create somewhere that was as environmentally-friendly as possible.

But at the same time, they wanted to live somewhere peaceful — they'd both grown up in a rural area and disliked urban life.

So the first thing they did was to look for a site.

And they found a disused stone quarry in a beautiful area.

The price was relatively low, and they liked the idea of recycling the land, as it were.

As it was, the quarry was an ugly blot on the landscape, and it wasn't productive any longer, either.

They consulted various architects and looked at a number of designs before finally deciding on one.

As I've said, it was a design for a sort of underground house, and it was built into the earth itself, with two storeys.

The north, east, and west sides were set in the earth, and only the sloping, south-FACING side was exposed to light.

That was made of a double layer of very strong glass.

There were also photovoltaic tiles fixed to the top and bottom of this sloping wall.

These are tiles that are designed to store energy from the sun.

And the walls had a layer of foam around them too, to increase the insulation.

Now, what is of interest to us about this project is the features which make the building energy-efficient.

Sunlight floods in through the glass wall, and to maximize it, there are lots of mirrors and windows inside the house.

That helps to spread the light around.

So that's the first thing — light is utilized as fully as possible.

In addition, the special tiles on the outside convert energy from the sun and generate some of the house's electricity.

In fact, and it's possible that in the future, the house may even generate an electricity surplus, and that the owners will be able to sell some to the national grid.

As well as that, wherever possible, recycled materials have been used.

For example, the floors are made of reclaimed wood.

And the owners haven't bought a single item of new furniture — they just kept what they already had.

And then there's the system for dealing with the waste produced in the house.

This is dealt with organically — it's purified by being filtered through reed beds which have been planted for that purpose in the garden.

So the occupants of the house won't pollute the land or use any damaging chemicals.

It's true that the actual construction of the house was harmful to the environment, mainly because they had to use massive amounts of concrete — one of the biggest sources of carbon dioxide in manufacturing.

And, as you know, this is very damaging to the environment.

In total, the house construction has released 70 tons of carbon dioxide into the air.

Now that's a frightening thought.

However, once the initial 'DEBT' has been cleared — and it's been calculated that this will only take ¹93.

FIFTEEN YEARS — this underground house won't cost anything — environmentally, I mean — because unlike ordinary houses, it is run in a way that is completely environmentally friendly.

So, eco-housing like this is likely to become much more...