unin 14 Roots教学目标
一、教学目标与要求
通过本单元教学，学生应能熟练地运用表示“希望、意愿、祝愿”的常用语；复习it的用法；了解19世纪欧美白人捕捉和贩运黑人作奴隶及虐待他们的罪恶历史。
二、教学重点与难点
1．重点词汇
become of, once in a while, provide, the moment, go back, role, reason
2．重点句型
1)Born a free man, he was now in Chairs．
2)What shocked him most was that the man who carried him were black．
3)Worse was to come．
4)All he knew was that his African ancestor taught his son and grandson the words in his own language for “river” and “guitar”!
3．语法it的用法
1)There's a knock at the door．Who is it?
2)It's a lovely baby．Is it a boy or a girl?
3)It is/has been three years since we last met．
4)It is necessary for you to do so．
5)It was in the street that I met him this morning.
教学建议
教学教法：高三下学期，教师按部就班的讲课文是不现实的。但高三下册书里却有很多精彩的文章及词汇，舍弃又未免可惜。把课文当作听力来上，即锻炼了听力，又培养了语感。如果听力与写作结合，学生的进步会更快。 写作可以练习听后写大意（main idea），写相关内容的文章。对于精彩段落，还可以练习听写整个段落。
词语辨析：
1．the moment
the moment作连词时和as soon as用法相当，用来引出一个时间状语从句。如：
I recognized Jack the moment he appeared in the street. 杰克在街上一露面，我就认出来了。
The moment (that) he said it he knew what a mistake he had made. 他一开口说那事，就知道自己犯了什么样的错误。
类似的名词除the moment 外, 如the minute，the second也可作连词用。在英国英语中 immediately也可作连词用，和as soon as用法一样。如：
I’ll tell him the minute (that) he gets here. 他一到达那儿，我就告诉他。
I left immediately the clock struck twelve. 钟一敲十二点我就离开了。
Please let me know immediately you get the results. 你一得到结果，请立即告诉我。
2.for和because的区别
for 和because都表示原因，但because是从属连词，连接原因状语从句，表示直接的，根本的理由；for是并列连词，连接两个并列分句，表示附加的推断的理由。如：
The light went out, because the oil was out. 因为油用完了，所以灯灭了。（直接的原因）
The oil must be out, for the light went out. 油想必用完了，因为灯灭了。（推断的理由）
3. be + to – v 常用来表示不可避免要发生的事，注定后来要发生的事。
They said goodbye, not knowing that they were never to meet again.
他们互相告别，不知道永远不可能再见面了。
The worst is still to come. 最严重的事情注定要发生的。
be + to-v 还常表示计划、打算或安排好做某事，应该或不应该做某事以及能不能做某事。如：
That book of yours is to appear next month. (= That book of yours is going to appear next month. )
你那本书将于下月出版。
You are not to smoke in the offices. (== You should not smoke in the offices. ) 你们不得在办公室吸烟。
What am I to do? ( = What should I /can I do?) 我该怎么办？
4.if only引起的句子表示一种难以实现的愿望，句子谓语要用虚拟语气。如：
It only he had had more courage! 要是他更勇敢些就好了！
If only she didn’t drive so fast! 但愿她开车不要太快！
If only it would stop raining! 雨要是停下来就好了！
5.make up one's mind, decide, determine
l）make up one's mini“决心；认定”，后接不定式或that从句，mind随人称而变化。如：
We've made up our minds to devote our lives to serving the people heart and soul．
2）decide指经过考虑或讨论研究作出决定，后接不定式，介词 on／up on或从句。如：
He decided on taking the position at the bank. ==He decided to take the position at the bank．
3）determine“决心、坚决”，侧重表示决心已下定，任何力量都动摇不了这种决心。其后常接不定式，也可接on／upon + ing。如：
His mother has determined to give him a chance．
6.seize，take，grasp，arrest
1）seize“抓住”有猛然抓住并不脱手之意。如：
The policeman seized the thief by the collar．
2）take“抓住”，属一般用语。如：
He took his girl friend by the arm．
3）grasp“抓住，抓紧；抱住；理解，领会”。如：
Grasp the rope and I'll pull you up．
I didn't quite grasp your meaning
4）arrest侧重于“逮捕；扣留；防止。”如：
He was arrested In suspicion of having murdered the girl．
This newly developed drug has arrested his cancer．
7.give out, give away, give back, give forth, give in, give off, give over, give up
（l）give out放出、发生；宣称，公布，发表；分配，分发；用完，耗尽；精疲力竭。如：
The nurse's patience at last gave out．
（2）give away赠送；出卖；泄露/give back归还；返射/give forth放出，发出（声音，气味等）；发表，公布give in投降；屈服，让步；交上／give off发出（蒸气、光、烟等）／give over移交，交托／give up让给；放弃，抛弃。
8. Once on the boat, they were taken below and their chains were fixed to bars that ran the length of the ship.
run在这里为引申含义，作“扩展，延伸”解。如：
The road runs along the river. 那条道路沿着河流延伸。
The shelves run round the wall. 书架绕墙而立。
9.All he knew was that his African ancestor taught his son and grandson the words in his own language for "river" and "guitar".
这是一个主从复合句。All the knew是主语，其中all后省略了关系代词that，he knew是定活从句。连词that后引导一个表语从句。
He can do all he could to help me. 他会尽其所能来帮助我。 (all that he could中的all that 可省略)
