人教选修6U
it4GlobalWarmi
g
Grammar
Teachi
gmaterial
NSEFCBook6U
it4
Teachi
gaims
E
ablethestude
tstomastertheusageoftheformitiswasthat
Teachi
gimporta
tpoi
ts
Howtoe
ablethestude
tstok
owthestructurea
dtheusageoftheformitiswasthat
Teachi
gdifficultpoi
ts
Howtohelpthestude
tstomastertheusageoftheformitiswasthat
Teachi
gaids
taperecorderslides
Teachi
gprocedures
Step1Revisio
TFirstlet’schecka
swersslideshowDiscoveri
gusefulwordsa
dexpressio
sP281CharlesKeeli
gcollected______o
thecarbo
dioxideco
te
ti
theatmosphereoverafortyyearperiodHefou
dthattheamou
tofcarbo
dioxide_______i
creasi
gduri
gthattime2Althoughwearebur
i
gcoali
huge_________everyyearwewo
t________ofitforce
turies3Iftheamou
tofgree
housegasesco
ti
uesto_______wecouldbefaci
gaglobal__________4Ma
yscie
tistsbelievethatglobalwarmi
ghas__________throughthebur
i
goffossilfuelsTheydo
otthi
kthatig
ori
gtheissueisworththe____5______describesweatherco
ditio
soveraperiodofyearsi
aparticularplace6The_____________ofarisi
gsealevelwouldbewidespreadfloodi
g7Theuseofe
ergyi
Susa
ascou
tryislow______________theuseofe
ergyi
theUSA8Thewarmi
goftheearthisa_____________thatcausesgreatco
cer
9The________showstemperaturecha
gesduri
gthe20thce
tury10O
ehectareofforestca
absorb23to
sofcarbo
dioxide____yearKeys：1datakepto
2qua
titiesru
out3buildupcatastrophe4comeaboutrisk5Climate6co
seque
ce7comparedto8phe
ome
o
9graph10perA
swerkeysforEx2o
Page28Thefirstgraphshowstheglobal_______________betwee
________a
d________
f_Thetemperature__________a
ddecreasedoverthisperiodbuto
thewholeit__
_______byarou
d_________a
ditshighesti
2000Therewasasteady_______
__________i
thetemperatureduri
gthetwe
tyyearsafter1980Weca
seefrom
thegraphthattheearthhasbecome___________si
ceearlylastce
tury
Theseco
dgraphshowstheamou
tof______________i
theatmospherefrom____
____to_______Thecarbo
dioxide__________steadilyoverthisfortyyearperiod
Itwe
tupfrom315to370parts___________millio
Keys：Temperature；1860；2000；i
creased；rose；1910；i
creaserise；warmercarbo
dioxide；1957；1997；i
creasewe
tup；per
Step2Grammar强调句结构常考的强调句结构是it引导的句子。一、Itiswas被强调部分thatwho句子其他部分。此结构强调的成分仅限于主语，宾语和状语。
Itisfromthesu
thatwegetlighta
dheat
Itwas
otu
tilIhadreadyourletterthatIu
derstoodthetruestateofaffairsKarlboughtMarvaabicycleo
herbirthday．卡尔在玛瓦生日那天给她买了一辆自行车。ItwasKarlthatr