必修三模塊四 Sandstorms in Asia學案
the desert is only 250 kilometers away to the west of beijing. to prevent it coming nearer, the government is planting trees.
(as to this part, listen to whole passage first, and then listen again paragraph by paragraph. after listening to a paragraph, ask students to look the screen and fill the blanks with their books closed.
step 4 language points in the text
t: now let’s deal with some language points.
◆ you just had to hope you’d survive.
survive vi. continue to live or exist ~ (from sth), ~ ( on sth),
e.g. many strange customs have survived from earlier time.
i can’t survived on 30£ a week.
vt. continue to live or exist in spite of nearly being killed or destroyed
~ an earthquake, ~ shipwreck
survivor n. person who survived
◆as a result of “ desertification”.
…. 由于沙漠化的結果
desert + ify “-fy / -ify” 后綴 變?yōu)関erb. desertify → desertification
◆ ……… because people cut down trees and dig up grass.
cut sth down (cause sth to fall down by cutting it at base)
~ a tree, 砍倒一棵樹，~ trousers, 改短褲子，~ one’s expenses, 減少開支
dig sth up ①break up(soil,etc) by digging， ②remove sth from the ground by digging
dig up the land for a new garden. 為建一座花園而墾地。
we dig up the tree by his roots.我們將樹連根拔起。
◆ …… weather experts advise people not to go out.
advise sb. (not) to do sth. give advice to sb; recommend
period 4 grammar (grammar 1&2)
step i presentation
t: look at the screen please. pay attention to the phrases in color. do they have something in common? what is the common thing?
1. to see her is to love her.
2. she likes to play with the child.
3. i am very glad to see you.
4. the next train to arrive was from new york.
5. i stayed there to see what would happen.
s: yes. they all have the word “to”.
t: very good. this is the grammar – infinitive structure we will learn this class. who knows what the infinitive structure is.
s: the infinitive structure is the phrase that has “to do sth”.
t: very good, but not always. infinitive structure has two types. one is to-infinitive, the other is bare infinitive. for example:
you cannot do better than go. (bare infinitive)
to see is to believe. (to-infinitive)
t: ok, let’s look some usages of the infinitive structure
① infinitive structure acts as subject.
e.g. to err is human. (subject)
it takes me ten days to finish this project. (英語中常用it做形式主語，真正的主語是 不定式)