Unit 4 Astronomy: the science of the stars（Vocabulary and Useful Expressions）
step 3 learning about numbers
t：maybe you have already noticed that there are a lot of numbers in the reading passage.to read them correctly is very important.sometimes there is a test on numbers in listening.
t：now turn to page 28 and look at part 3.match each word to the number that has the same meaning.
（allow ss several minutes to finish the task.）
t：now let’s check your answers.
s：a.90% ninety percent
b.10000 ten thousand
c.1000000 one million
d.150000 one hundred and fifty thousand
e.75% seventy-five percent
f.1/3 one-third
g.500 000 half a million
h.2/3 two-thirds
step 4 important points
t：in the reading passage of this unit，there are some important words and expressions.i will first give you five minutes to pick out the difficult words，expressions and sentence patterns.you may work with your partner.
（after five minutes.）
s1：in the first paragraph，“... the water pipes in some buildings cracked and burst.” how can we understand “burst”？
t：if something bursts or if you bursts it，it breaks open or apart suddenly and violently so that its contents come out.
e.g.you are going to burst the balloon，if you are not careful.
s2：in the first paragraph，“farmers’ wives noticed that the well walls had deep cracks in them.” and in the second paragraph “a huge crack that was eight kilometers long and thirty meters wide.” do the two “cracks” have the same meaning？
t：you are very careful.yes，they have the same meaning.both of them are nouns.“crack” means a very narrow space between two things or two parts of something.“crack” can also be a verb，meaning to break or make something break so that it gets one or more lines on its surface，as in the sentence “in the city，the water pipes in some buildings cracked and burst.”
e.g.she fell off her bike and cracked a bone in her leg.
s3：how can we understand this sentence in the second paragraph “it seemed that the world was at an end.”？
t：in order to understand this sentence，you have to know the meaning of the phrase “be at an end”.it refers to a situation in which something is finished or no longer existed.
e.g.the long hot summer was at last at an end.
other examples are “come to an end”，“put an end to sth.”.
t：so now who can explain the sentence in our text？
s4：let me have a try.the earthquake was so terrible that nearly everything was destroyed.so people thought it was the end of the world.