单选题_____ from the hill-top the lake scenery is beyond description.A To seeB SeeingC SeenD Having

共用题干
第三篇

The Exploding Lakes of Cameroon

What comes to mind when you think of a lake?You probably imagine a pretty scene
with blue water,birds,and fish.For the people in the northwestern Cameroon,however,
the image is very different.For them,lakes may mean terrible disasters.In 1984,
poisonous gases exploded out of Lake Monoun and came down into the nearby villages,
killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled
down the hills and into the valleys and killed 1,700 people.
Lake Nyos and Lake Monoun are crater（火山口）lakes. They were formed when
water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake
Monoun are not active anymore.However,poisonous gases from the center of the earth
continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.
In most crater lakes,these gases are released often because the water"turns over"
regularly.That is,the water from the bottom of the lake rises and mixes with the water at
the top,allowing the gases to escape slowly.
However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows
the reason for this fact,but as a result,these lakes have more gases trapped at the bottom
than other crater lakes.In fact,scientists who have studied Lakes Nyos and Monoun have
found 16,000 times more gases.When a strong wind,cool weather,a storm,or a
landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent
explosion.
In the past,no one knew when the gases might explode,so there was no way for the
villagers to escape disaster. Now scientists from the United States,France,and
Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They
stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the
bottom and the other end in the air. Near the top of the pipe,the team put several holes
that could be opened or closed by a computer.Now,when the gas pressure gets too high,
the holes are opened and some of the gas-filled water shoots up through the pipe into the air
like a fountain.With less pressure,a disastrous explosion is much less likely.However,
the scientists are not sure that one pipe will be enough to prevent explosions.They hope to
put in others soon and they plan to install a similar pipe and a computer system at Lake
Monoun as well.
To protect people nearby until all of the pipes are in place,the scientists have installed
early warning systems at both lakes.If the gas pressure rises to a dangerous level,
computers will set off loud sirens（警报）and bright lights to warn the people in the villages.
That way,they will have time to escape from the dangerous gases.

A team of scientists has
A:erected a pressure-releasing pipe in the lake.
B:identified the gases at the bottom of the lake.
C:built a beautiful fountain near the lakes.
D:removed all dangerous gases from the lakes.

资料：Happy wood sprites knows the way to Fenghuang city.
Happy wood sprites will hold a big party along the Spirit Lake tonight
The Spirit Lake is located in North-east of here
The density of tree branches and leaves could tell direction. Generally ,the direction that has More branches and leaves is the south.
According to astrology,you could determine direction. Firstly, you should find the adle Big Dipper. In the direction of the handle you can find Poiaris and that direction is the north.
打开信封，里面是一个请柬
A recital of poems by Barbie Mariposa that retell
legends from the tribal culture of the Spirit Lake.
Accompaniment by Happy wood sprites who will be
playing harp native spirit Lake instruments from
his private collection
Green spinach salad with vinaigrette dressing
Cream of mushroom soup
Grilled salmon with choice of either roasted squash
or steamed broccoli
Lemon meringue tart
Dinner will start promptly at midnight and end
before sunrise is Tree House of Spirit Lake .
Formal Dressing requires.

How is the fish prepared?

A.It is creamed
B.It is steamed
C.It is grilled
D.It is roasted

The big lake was contaminated with waste waters from nearby factories.

A:widened
B:blackened
C:polluted
D:mixed

共用题干
The Exploding Lakes of Cameroon
What comes to mind when you think of a lake?You probably imagine a pretty scene with blue water, birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them, lakes may mean terrible disasters.In 1984,poisonous gases exploded out of Lake Monoun and came down into the nearby villages,killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.
Lake Nyos and Lake Monoun are crater（火山口）lakes.They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.
However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottom than other crater lakes.In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.
In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster.Now scientists from the United States,France,and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.Near the top of the pipe,the team put several holes that could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.
To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level,computers will set off loud sirens（警 报）and bright lights to warn the people in the villages.In that way,they will have time to escape from the dangerous gases.

Which of the following statements about Lake Nyos and Lake Monoun is true?
A:They were formed in 1984.
B:They are at the top of two active volcanoes.
C:They are not like most other crater lakes.
D:Water in them turns over regularly.

共用题干
The Exploding Lakes of Cameroon
What comes to mind when you think of a lake?You probably imagine a pretty scene with blue water, birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them, lakes may mean terrible disasters.In 1984,poisonous gases exploded out of Lake Monoun and came down into the nearby villages,killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.
Lake Nyos and Lake Monoun are crater（火山口）lakes.They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.
However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottom than other crater lakes.In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.
In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster.Now scientists from the United States,France,and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.Near the top of the pipe,the team put several holes that could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.
To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level,computers will set off loud sirens（警 报）and bright lights to warn the people in the villages.In that way,they will have time to escape from the dangerous gases.

What do we learn from the last paragraph?
A:Scientists are planning to install pipes in all crater lakes.
B:Scientists still do not know how to prevent gas explosions.
C:Explosion disasters could be avoided in the future.
D:Warning systems have been set up in the villages nearby.

This poem depicts the beautiful scenery of a town in the South.

A: praises
B: writes
C: imitates
D: describes

The largest lake in Britain is( ).

A.the Lake Neagh
B.Windermere Water
C.Coniston Water
D.the Lake District