loader懂你英语 Level5 Unit1 Part4

2021年1月9日发(作者：施立明)
L5-U1-P4 英语流利说 5-1-4 懂你英语 Level5 Unit1 Part4
L5-U1-P4-1 Listening : Mysteries of Nature 1
There are many mysteries in nature.
Mysteries are things we don't understand, such as how the Egyptian
pyramids were built.
In fact, we are surrounded by mysteries.
What we know about the world seems like very little.
Thing we don't understand are ...mysteries.
Mysteries are things we don't understand, such as
how
the Egyptian
pyramids
were built
.
Scientists tell us that what we see in the universe is only a small
part of what is there.
The rest is invisible, including dark matter and dark energy.
These two unknowns make up around 95% of the universe.
Evidence for their existence comes from their effects on what we can
observe, such as the motion and positions of distant galaxies.
Most of what makes up the universe is
invisible.

Evidence for their
existence
comes from their
effects
on what we
can
observe
, such as the
motion
and positions of distant
galaxies.
(1) Scientists tell us that what we see in the universe is only a
small part of what is there.
(2) The rest is invisible, including dark matter and dark energy.
(3) These two unknowns make up around 95% of the universe.
(4) Evidence for their existence comes from their effects on what
we can observe, such as the motion and positions of distant galaxies.
The
rest
is
invisible
, including dark
matter
and dark energy.
Yet, though we know very little, we are able to build airplanes and
communicate with smart phones.
In some ways we humans are very smart, or at least we think we are.
We still need to face big issues, like climate change, and that is
going to be a huge challenge.
The challenge for humans will be our ability to adapt to our changing
environment.
What's an example of a big issue?
- global warming.
There are many mysteries in nature.
In fact, we are surrounded by mysteries.
In some ways we humans are very smart, or at least we think we are.
Mysteries are things we don't understand, such as how the Egyptian
pyramids were built.

We still need to face big issues, like climate change, and that is
going to be a huge challenge.

The
challenge
for humans will be our
ability
to
adapt
to
our
changing
environment.
There are many mysteries in nature.
What we know about the world seems like very little.
In some ways we humans are very smart, or at least we think we are.
Mysteries are things we don't understand, such as how the Egyptian
pyramids were built.

We still need to face big issues, like climate change, and that is
going to be a huge challenge.

What about other forms of life?
How do they adapt?
Seasonal variations, for example, can be one of the greatest
challenges for animals to overcome.
Overcoming such challenges is a great achievement, but hardly easy.
Some birds migrate thousands of kilometers each year to deal with
seasonal changes.
These migrations are amazing.
Why do birds migrate?
- to deal with seasonal changes.
Overcoming such
challenges
is a great
achievement
,
but
hardly
easy.
Birds don't carry maps or compasses, yet they know where to go.
They have developed the ability to see the Earth's magnetic field.
This ability is a wonder of nature.
It takes advantage of the fact that the Earth is like a huge bar
magnet.
It has a north pole, which is positive, and a south pole, which is
negative.
Somehow the birds are able to see this magnetic field and use it to
their advantage.
What ability do birds have to help them navigate?
-They can see the
Earth's magnetic field.
Somehow the birds are
able
to see this magnetic field and
use
it
to their
advantage
.
And even the way birds fly together is amazing.
Many migrating birds fly in a V formation.
They do this to conserve energy.
In a V formation, birds can use the energy of the birds in front of
them.
This energy comes from the air currents generated by the wings.
Conserving energy is necessary for the birds to survive the long
journey.
How do the birds know this?
It's truly amazing how the birds know this.
Why do birds fly in a V formation?
to conserve energy.
Some birds migrate thousands of kilometers each year to deal with
seasonal changes.
They have developed the ability to see the Earth's magnetic field.
This energy comes from the air currents generated by the wings.
Seasonal variations, for example, can be one of the greatest
challenges for animals to overcome.

Overcoming such challenges is a great achievement, but hardly easy.

Conserving energy is
necessary
for the birds to
survive
the
long
journey
.
Some birds migrate thousands of kilometers each year to deal with
seasonal changes.
Conserving energy is necessary for the birds to survive the long
journey.
This energy comes from the air currents generated by the wings.
Seasonal variations, for example, can be one of the greatest
challenges for animals to overcome.

Overcoming such challenges is a great achievement, but hardly easy.


L5-U1-P4-2 Listening : Mysteries of Nature 2
Another amazing example of survival is the salmon.
Salmon spend most of their lives in the ocean, which is saltwater.
Yet, when it's time to breed, they do so in freshwater rivers.
Salmon can adapt their bodies to survive in both saltwater and
freshwater.
When it's breeding time, they return to the same river where they
were born.
It seems as if they have a built-in map that guides them for hundreds
of miles.
Where do salmon spend most of their lives?
- in the ocean
(1) Another amazing example of survival is the salmon.
(2) Salmon spend most of their lives in the ocean, which is saltwater.
(3) Yet, when it's time to breed, they do so in freshwater rivers.
(4) Salmon can adapt their bodies to survive in both saltwater and
freshwater.
Once they leave the saltwater, they don't eat.
They are determined to finish their journey, despite the many
obstacles.
They swim against strong currents, jump over waterfalls and try to
escape the claws of hungry bears.
Many die along the way, but enough of them survive to breed and produce
the next generation.
Once they have laid their eggs, they die, having completed their
journey.
It seems that their purpose in life is just to reproduce.
What do they do after laying the eggs?
- they die
They swim
against
strong
currents
, jump over waterfalls and try
to
escape
the claws of hungry
bears
.
Migration takes animals to new, more favorable environments when the
seasons change.
Some of these journeys are long and dangerous, along routes with no
obvious landmarks.
The longest migration is that of the Arctic tern.
It flies from pole to pole, twice a year.
If a tern achieves its average lifespan of 20 years, the distance
it has flown will be equivalent to a journey to the moon and back.
A landmark is something easy to see and remember, like ...a river
or bay.
Some of these
journeys
are long and dangerous, along
routes
with
no
obvious
landmarks.
Humans also migrate, but seldom if ever for seasonal variations.
Unfortunately, human migrations are often due to human activities.
Since the beginning of the 21st century, large scale migrations have
become a global problem.
Millions of migrants have had to leave their countries and look for
new homes.
Many have died along the way or lived as refugees in camps until they
are admitted into a new country.
So the question remains as to how our global community will face these
challenges.
Most human migrations are due to...
human activities
.
Humans also
migrate
, but seldom if
ever
for seasonal variations.
Unfortunately, human migrations are
often
due to
human
activities
.
Since
the beginning of the 21st century, large
scale migrations have become a global
problem
. Millions
of
migrants
have had to leave their countries and
look
for new
homes.
Salmon spend most of their lives in the ocean, which is saltwater.
It seems that their purpose in life is just to reproduce.
Unfortunately, human migrations are often due to human activities.
Since the beginning of the 21st century, large scale migrations have
become a global problem.

Some of these journeys are long and dangerous, along routes with no
obvious landmarks.


L5-U1-P4-3 Vocabulary : Social Relations
To criticize someone is to point out their faults or mistakes.
Some people appreciate constructive criticism, which can help them
develop their skills.
Some people cannot
take
any
criticism
without feeling
hurt
.
Learning how to
provide
and take constructive
criticism
is an
important
skill
.
To praise someone is to let them know that they have done a good
job.