人教版（新课程标准） 必修4 Unit 2 Working the land Reading -chemical or organic farming(共31张PPT)

(共31张PPT)
Unit
2
Working
the
Land
Chemical
or
Organic
Farming?
In
this
unit
we
have
learnt
about
a
great
man,
do
you
still
remember
who
he
is?
Step
Ⅰ.
Leading-in
Yuan
Longping
-------Father
of
Hybrid
Rice
Super
hybrid
rice
What
is
his
achievement
?
Can
you
think
of
other
ways
to
increase
our
crop
harvest?
What
makes
crops
grow
faster
&
better
?
Step
Ⅱ.Brainstorm
It
is
fertilizer.
fertilizer
How
many
kinds
of
fertilizers
do
you
know?
There
are
two
kinds.
chemical
fertilizers
natural
fertilizers
chemical
farming
organic
farming
chemical
fertilizers
natural
fertilizers
Better
？
Chemical
or
organic
farming?
P14.
Step
Ⅲ.
Reading
Read
the
passage
quickly
and
try
to
find
out
the
main
idea
of
the
each
paragraph.
Pay
attention
to
the
key
word(s)
in
each
paragraph.
Task
1.
Skimming
D.
Long-term
use
of
chemical
fertilizers
can
cause
damage
to
the
land
and
people’s
health.
C.
Problems
caused
by
chemical
fertilizers.
P1.
P2.
B.
Farmers
and
customers
turn
to
organic
farming.
A.
Other
methods
to
keep
the
soil
fertile.
P3.
P4.
Main
idea
of
the
each
paragraph.
Chemical
fertilizers
can
cause
many
problems,
so
organic
farming
is
becoming
more
popular.
Organic
farming
means
growing
crops
with
natural
fertilizer.
The
organic
farmers
keep
the
soil
rich
and
healthy.
The
main
idea
of
the
text:
Task
2.
Careful
reading
Listen
to
the
tape
and
pay
attention
to
the
pronunciation.
2.
Underline
the
useful
and
important
words
and
expressions.
1.
Which
statement
is
WRONG
according
to
the
text
?
A.
All
crops
are
organic.
B.
Recently,
the
term
“organic
farming”
has
gained
another
meaning.
C.
All
farmers
use
fertilizers.
D.
Scientists
believe
some
chemical
fertilizers
are
better
for
people.
D
2.1.
Choose
the
best
answer.
2.
Which
is
NOT
the
reason
why
organic
farmers
prefer
natural
waste
from
animals?
A.
It
can
keep
the
food
free
from
chemicals.
B.
It
can
keep
the
air,
soil
and
water
free
from
chemicals.
C.
It
can
kill
harmful
pests.
D.
It
can
make
the
soil
richer
in
mineral.
C
3.
What
is
the
advantage
of
using
chemical
fertilizers?
A.
Leaving
chemicals
in
the
ground
for
a
long
time
is
good
for
water
supply.
B.
They
can
get
the
soil
exhausted.
C.
They
can
kill
helpful
bacteria.
D.
They
can
kill
harmful
pest.
D
4.
The
organic
farmers
do
the
followings
except
______.
A.
adding
fertilizers
which
is
rich
in
mineral
B.
changing
crops
every
two
or
three
years
C.
planting
seeds
in
different
layers
of
the
soil
D.
planting
grass
between
crops
to
prevent
the
soil
from
being
blown
away
A
1.
Why
are
chemical
fertilizers
so
popular
in
farming
today?
2.What
problems
can
be
caused
by
using
chemical
fertilizers?
3.What
is
organic
farming?
4.What
is
the
main
reason
for
using
organic
farming
methods?
2.2.Answer
the
following
questions.(P14.
Ex.1)
Why
are
chemical
fertilizers
so
popular
in
farming
today?
They
are
a
great
way
to
stop
crop
disease
and
increase
production.
2.
What
problems
can
be
caused
by
using
chemical
fertilizers?
They
can
damage
the
land
by
killing
helpful
bacteria
and
pets
and
by
staying
in
the
ground
and
underground
water
for
a
long
time.
They
damage
people’s
health
by
building
up
in
their
bodies
and
leading
to
cancer
or
other
illnesses.
3.
What
is
organic
farming?
Organic
farming
means
growing
crops
without
using
any
chemicals.
The
main
reason
for
using
organic
farming
methods
is
to
grow
good
food
and
to
avoid
damaging
the
environment
or
people’s
health.
4.
What
is
the
main
reason
for
using
organic
farming
methods?
In
recent
days,
scientists
have
discovered
that
using________
fertilizers
for
a
long
time
can
hurt
the
land
and
also
people's
_______.
There
are
several
__________
caused
by
chemical
fertilizers.
They
hurt
the
health
of
the
land,_____
in
the
water
for
a
long
time
and
get
into
people's
________
through
their
food.
chemical
bodies
problems
health
stay
Fill
in
the
blanks
according
to
the
passage.
Step
Ⅳ.
Retelling
&
Summary
________
farming
is
becoming
more
popular
with
some
farmers
and
many
_________
after
these
discoveries
came
out.
Organic
farming
does
not
use
any
chemicals.
There
are
many
organic
farming_________
for
making
the
land
healthy
and
productive.
All
of
these
methods
try
to
produce
good
food
and
to
keep
the
_____________and
people
________.
methods
healthy
environment
customers
Organic
Step
Ⅵ.
Homework
Read
the
passage
more
carefully
after
class,
and
find
some
useful
language
points.
Finish
the
exercises
on
workbook
P49~50.
Thank
You
!
…
killing
the
helpful
bacteria
and
pests
as
well
as
the
harmful
ones.
as
well
as
“(除
...
之外)也，又”
,可连接并列的单词或短语
He
grows
flowers
as
well
as
vegetables.
A
teacher
should
entertain
as
well
as
teach.
It
is
unpleasant
in
summer
as
well
as
in
winter.
Language
points
as
well
as=not
only…but
also，但两者在用法上有如下不同
not
only…but
also侧重后者，as
well
as则着重前者，也就是说A
as
well
as
B=
not
only
B
but
also
A。例如：
Mr.
Brown
has
experience
as
well
as
knowledge.
布朗先生不仅有知识而且有经验。（侧重前者，即experience。）
Mr
Brown
has
not
only
knowledge
but
also
experience.）（着重后者，即but
also后面的部分。）
2.
Many
of
these
chemicals
can
lead
to
cancer
or
other
illnesses.
lead
to
导致；造成
(to是介词，后
接名词或动词-ing形式)
Too
much
work
and
too
little
rest
often
lead
to
illness.
Heart
failure
led
to
her
father’s
death.
lead
to
(道路)通向；通往
The
street
leads
to
the
supermarket.
turn
to
求助于，转向
3.
…
many
customers
are
beginning
to
turn
to
organic
farming.
I
tried
to
stand
on
my
own
two
feet
rather
than
turned
to
my
parents.
We
can
turn
to
him
for
help.
turn
on
打开，
开启
turn
off
关掉
turn
down
调小
turn
up
调大
turn
against
sb/sth
转而讨厌、反对某人某事
turn
out
to
be
最后结果，最终成为
turn
into
sth使......变成
turn
in
交还，交回
turn
back
掉转头
turn
over翻转
4.
This
also
keeps
the
air,
soil,
water
and
crops
free
from
chemicals.
keep
…
free
from
/
of
使…
免受(影响、伤害等)
We
put
our
books
in
the
bookcase
to
keep
them
free
from
dust.
keep
oneself
from
doing
sth.
克制自己不做某事
She
could
hardly
keep
herself
from
laughing.
keep
sth.
from
sb.不将某事告诉某人
I
think
we
ought
to
keep
the
truth
from
him
until
he’s
better.