Lesson 5 No Wrong Numbers
无错号之虞
First listen and answer the question
听录音回答问题
What does”No wrong numbers”mean?
无错号之虞是什么意思？
Mr.James Scott has a garage in Silbury and now he has just bought another garage in Pinhurst.Pinhurst is only five miles away from Silbury,but Mr.Scott cannot get a telephone for his new garage,so he has just bought twelve pigeons.Yesterday,a pigeon carried the first message from Pinhurst to Silbury.The bird covered the distance in three minutes.Up to now,Mr.Scott has sent a great many requests for spare parts and other urgent messages from one garage to the other.In this way,he has begun his own private”telephone”service.
詹姆斯·斯科特先生在锡尔伯里有一个汽车修理部，现在他刚在平赫斯特买了另一个汽车修理部。平赫斯特离锡尔伯里只有5英里，但詹姆斯·斯科特未能为它的另一个汽车修理部弄到一部电话机，所以他买了12只鸽子。昨天，一只鸽子把第一封信从平赫斯特带到锡尔伯里。这只鸟只用了3分钟就飞完了全程。到目前为止，斯科特从一个汽车修理部向另一个发送了大量索取备件的信件和其他紧急函件。就这样，他开始了自己的私人“电话”业务。
Key structure 关键句型
What happened?What has happened?一般过去时和现在完成时
What happened?一般过去时：
在第3课里出现了一般过去时，一般过去时用来表示过去某一特定时间发生的动作或者事情，因此，句中常有表示过去某一时刻的短语,以下句子注意斜体字。
如：
I wrote to him last month.上个月我给他写了信。
I bought this car last year.去年我买了这辆车。
He came to see me this morning.今天上午他来看我。
I saw him ten minutes ago.我10分钟以前见到了他。
What has happened?现在完成时
在第4课里出现了现在完成时，现在完成时用来表示发生在过去但对现在仍有影响的一个动作。在现在完成时的句子中常有一些表示时间的词和短语。注意以下句子中的斜体字-时间状语。
The train has just left the station.火车刚刚驶离车站。
I’ve already seen that film.那个电影我已经看过了。
He has been abroad for six months.他在国外已6个月了。
Have you ever met him before?你之前见过他吗？
I have never met him before.我从未见过他。
I have not finished work yet.我还没完成工作。
There have been a great number of accidents lately.最近事故很多。
Up till now he has won five prizes.迄今为止他已经赢了5个奖。
具体讲解：
1）过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是result (结果）。
2）过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。一般过去时的时间状语:
yesterday, last week，…ago, in1980, just now, 具体的时间状语
共同的时间状语:
this morning, tonight, this April, now, once，before, already, recently，lately
现在完成时的时间状语
for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,
不确定的时间状语
3）现在完成时可表示持续到现在的动作或状态，动词一般是延续性，如live, teach, learn, work, study, know.
过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等。
举例：
I saw this film yesterday.
（强调看的动作发生过了。）
I have seen this film.
（强调对现在的影响，电影的内容已经知道了。）
Why did you get up so early?
（强调起床的动作已发生过了。）
Who hasn't handed in his paper?
（强调有卷子，可能为不公平竞争。）
She has returned from Paris.
她已从巴黎回来了。
She returned yesterday.
她是昨天回来了。
He has been in the League for three years.
(在团内的状态可延续)
He has been a League member for three years.
(是团员的状态可持续)
He joined the League three years ago.
( 三年前入团，joined为短暂行为。)
I have finished my homework now.
---Will somebody go and get Dr. White?
---He's already been sent for.
句子中如有过去时的时间副词（如 yesterday, last, week, in 1960）时，不能使用现在完成时，要用过去时。
（错）Tom has written a letter to his parents last night.
（对）Tom wrote a letter to his parents last night.
用于现在完成时的句型
1）It is the first / second time…. that…结构中的从句部分，用现在完成时。
It is the first time that I have visited the city.
It was the third time that the boy had been late.
2）This is the… that…结构，that从句要用现在完成时.
This is the best film that I've (ever) seen.
这是我看过的最好的电影。
This is the first time (that) I've heard him sing.这是我第一次听他唱歌。