九年级英语第十八单元Planting trees 植树

This must be done as soon as possible .
②must be 表示一种推测，意思是“大概是”，“可能是”，“准是”，如：
He must be in the workplace now .
Grandpa Li must be over seventy now .
I\'m afraid you must be right .
Ah ! it must be more delicious !
③must be 表示“必须是”，“一定是”。如：
The ground must be just right — Neither too wet nor too dry .
The answers must be right .
24 . 表示命令、请求和指示的交际用语
［释疑］命令、请求或指示对方干什么或不要干什么，在英语中最常用的是第二人称祈使句，主语 you 通常不表示出来。祈使句的肯定式以原形动词开始，句首或句尾可以加 please ; 祈使句的否定式以“Don\'t + 动词原形”开始。例如：
Put the tree in the hole so that it is straight .
Water the trees as often as possible .
Don\'t dig the hole too large .
25 . It\'s best to do sth . 最好是…… ( 干某事 )
［释疑］这是表示建议的交际用语，意思相当于“You\'d better do sth . ” ( 你最好干某事 ) 。如 It\'s best to plant trees in spring because it\'s warmer . ( = You\'d better plant trees in spring because it\'s warmer . )
It\'s best to water well when the earth is dry .
It\'s best to fill in the hole with earth .
It\'s best to harvest at the right time .
It\'s best to come to school in your old clothes tomorrow because we are going to plant trees in the park .
【 妙文赏析 】
The Lose Outweights the Gain
Joel Adams laments , “When we went on vacation two years ago , burglars broke in and stole ＄250 . So , last year I got smart , I left all the lights on and turned on all the radios and TV s . The burglars were afraid to show up and didn\'t get a cent — but the electric company got ＄523 ! ”
得不偿失
乔尔•亚当斯悲叹道：“两年前我们外出度假，家里没有人，小偷撬门进来偷走了250
美元。去年我学聪明了。我把屋里所有的灯、收音机和电视都打开。小偷不敢来了，一分钱
都没偷走，可电力公司向我们要去了523美元 ! ”
【 思维体操 】
你能猜出下列谜语吗 ?
1 . What letter is a drink ?
2 . What letter is a part of the face ?
3 . What letter is an insect ?
4 . Which letter goes all around an is land ?
5 . What changes a pear into a pearl ?
6 . What is the most important thing in the world ?
7 . What is that which is seen twice in “every day”and four times in“every week”yet only once in“a year” ?
8 . Why is the letter B like fire ?
9 . Why is the letter F like a cows tail ?
10 . What part of London is in France ?
11 . Why is the letter G like the sun ?
12 . Why is the letter T like an is land ?
13 . Why is U the happiest letter ?
14 . Which letter is most useful to a deaf woman ?
15 . What letter in the alphabet and travel the greatest distance ?
16 . What is the end of everything ?
17 . In what way are the letter O and E neatly keep house a like ?
18 . What does the letter B do for boys as they grow up ?
19 . Why is a sewing machine like letter S ?
20 . Why is a false friend like the letter P ?
1 . T ( tea ) 2 . I ( eye ) 3 . B ( bee ) 4 . C ( sea ) 5 . L 6 . The letter E , because it is first in everything and everybody . 7 . Letter E . 8 . because it makes oil boil . 9 . Because it is at the end of beef . 10 . The letter N . 11 . Because it is the center of light . 12 . Because it is in the middle of water . 13 . Because it is always in the midst of fun . 14 . The letter A , because it makes HER HEAR , 15 . The letter D , because it goes to the end of the world 16 . The letter G . 17 . Both are always in order . 18 . As they grow older it makes them bolder . 19 . Because it makes needles needless . 20 . Because he is the first in pity , but the last in help .
三、智能显示
【 心中有数 】
单元语法发散思维
※ 含有情态动词的被动态
含有情态动词的被动结构是：情态动词 + be + 及物动词的过去分词。如：
We must find out the truth . → The truth must be found out .
These machine parts may be needed in our work .
Should an article be used here ?
These stairs are very dangerous . They should be repaired .
This lesson must be gone over again .
※ 被动语态与系表结构的区别
动词 be + 过去分词这个结构并不定都是被动语态结构，有时它可能是 be + 过去分词 ( 作表语 ) 的系表结构。因此：
be + 过去分词 ( 被动语态 ) 与 be + 过去分词 ( 作表语 ) 这两种结构的主要差别是：
①被动结构表示一个动作，带表语的结构表示主语的特点或所处的状态。如：
The library is now closed . ( 系表结构 )
It is usually closed at 6 . ( 被动结构 )
②被动结构后面可带 by + 实施动作者，而系表结构一般没有。如：
The glass is broken . ( 系表结构 )
It was broken by my sister . ( 被动结构 )
③“系表结构”中的过去分词可以被 well , very 等副词修饰，而“被动结构”中的
过去分词则一般不能如此。如：
The

《九年级英语第十八单元Planting trees 植树(第5页)》