Unit 1 Life on Mars教案
this is the most crowded street in shanghai.
the bus is crowded with people who go to work.
15. a number of , the number of 的區別
a number of = numbers of + 可數名詞的復數+ 動詞形式為復數
a number of visitors come to suzhou every day.
the number of + 名詞的復數+ 動詞的三單 意思是“……的總和數量
the number of the students in our class is 65.
16. at half the speed of light 以光速的一半（行駛）， at ( 以……速度,價格等)
eg：the car is running at 80 kilometres an hour.
i bought it at a low price.
17. three-eighths 八分之三，在分數詞的表述中，記住口訣“分子基數詞分母序數詞，分子大于1，分母加s”。
如： 1/3 one third 5/6 five sixths
eg: two thirds of the students in our class are boys.
18. every 和each的共同點和不同點
（1）every 和each后加單數名詞，動詞用第三人稱單數形式。
eg: each of the boys in class 2 has bought the book.
eg: every student is listening to the teacher carefully.
（2）each是一定數目中的每一個，強調“個別”“各有不同”，each是代詞，可以和of 連用。
every 只數目不確定中許多人或物中間的“每一個”，強調“總和”更強調“大家一致”。every 后不可以跟of
二. 重點短語
1.be cared for by 2. be able to travel in space
3.wear space helmets to go outside 4.in the form of pills
5.make people feel very ill 6.live on other planets
7.move to mars 8.at the moment
9.become more and more crowded 10.build a better world
11.too slow to carry large numbers of people 12.travel at half the speed of light
13.need food, water and air to survive 14.three-eighths of the gravity on earths
15.float away into space 16.prevent/keep/stop sb from doing
17.wear special boots to make themselves heavier 18.compared with life on mars
19have more space 20.live in a dome with ten bedrooms