區(qū)別：現(xiàn)在完成時(shí)側(cè)重于動(dòng)作的結(jié)速或完成；而現(xiàn)在完成進(jìn)行時(shí)側(cè)重于動(dòng)作的未結(jié)束和繼續(xù)進(jìn)行。

例：1)I have opened the can.

　　 2) I have been writing the letter since then.

1、現(xiàn)在完成進(jìn)行時(shí)的形式：

1)主動(dòng)語(yǔ)態(tài)：主語(yǔ)+have/has+現(xiàn)在分詞(doing)

2)被動(dòng)語(yǔ)態(tài)：主語(yǔ)+have/has been+過去分詞(done)

例：Have you been waiting for him all the day?

3、幾種時(shí)態(tài)表示同一意思

例：1)He left china two years ago.

　　 2)It is two years since he left china.

　　 3)He has away from china for 2 years.

2、today等時(shí)間狀語(yǔ)的運(yùn)用

運(yùn)用today，this morning，this afternoon等時(shí)間狀語(yǔ)時(shí)，時(shí)態(tài)要根據(jù)說話的具體情況而定。

例：1)He didn’t do his homework this afternoon.他今天下午沒有做功課。

　　　 He hasn’t done his homework this afternoon.他今天下午還沒有做功課呢。

　　 2)He arrived here a little late today,because he got up late and didn’t catch the bus.

　　 3)He has been very busy today.(截至到說話時(shí)，仍是在今天，他們很忙)

1、just now和just的區(qū)別　　　 just now用在一般過去時(shí)

just用在現(xiàn)在完成時(shí)

例：1)We had an English lesson just now.

2) We have just had an English lesson.

4．表示完成，結(jié)果的現(xiàn)在完成時(shí)

例：1)My father has just gone out.(結(jié)果)

　　 2)I have closed the window.(完成)

　　 3)Mr.Li has gone to Australia.(結(jié)果)

A→表示完成的用法

I’ve just finished my homework.

They have gone to GuiLin.

B→表示結(jié)果的用法

例1、(1)I opened the door.

　　 (2)The door is open now.

　　 (3)I have opened the door.

例2、(1)John bought a dictionary.

　　 (2)Now John has a new dictionary.

　　 (3)John has bought a new dictionary.

▲牢記：表結(jié)果的現(xiàn)在完成時(shí)常見動(dòng)詞。

make　 become　 go　 come　 lose　 grow　 sell　 buy　 fall

C→常見的時(shí)間狀語(yǔ)(副詞)

already　 just　 yet→句末

　　　 句中

3、表示經(jīng)驗(yàn)的現(xiàn)在完成時(shí)

例：1)肯定句：I have seen the film three times.

2) 否定句：I’ve never seen the film.

3)疑問句：Have you ever been to U.K.?

A→基本用法

表示經(jīng)驗(yàn)的現(xiàn)在完成時(shí)，說明從過去起到現(xiàn)在的經(jīng)驗(yàn)，即從過去到現(xiàn)在之間曾經(jīng)經(jīng)歷過或做過的事情。

B→常用的時(shí)間狀語(yǔ)

　 Often, ever, before, never, once, twice, times, many times

C→ have/has been的用法

例：a.　 have been to

I have been to the summer palace twice.(經(jīng)驗(yàn))

I have been to the museum to see the exhibition.(完成)

　 　b. have been in

Have you ever been in America?(經(jīng)驗(yàn))

We have been in home for the whole day.(繼續(xù))

插曲：be 動(dòng)詞的過去分詞

Be動(dòng)詞的過去分詞不管主語(yǔ)的人稱和數(shù)都要用been表示

例：We have been tired these days

區(qū)別：I am happy.(一般現(xiàn)在時(shí))

　　　 I was happy.(一般過去時(shí))

　　　 I have been happy.(現(xiàn)在完成時(shí))

2、表示繼續(xù)的現(xiàn)在完成時(shí)

例：1)肯定句：Li Ming’s elder brother has studied in Beijing university for about three years.

　　 2)否定句：We haven’t seen each other all this month.

　　 3)疑問句：How long have you know your boy friend?

A→基本用法

表示繼續(xù)意義的現(xiàn)在完成時(shí)，說明過去的動(dòng)作一直延續(xù)到現(xiàn)在，也就是說從過去某時(shí)開始

的動(dòng)作、狀態(tài)一直持續(xù)到現(xiàn)在。此時(shí)，往往用和現(xiàn)在有關(guān)的表示一段時(shí)間的時(shí)間狀語(yǔ)。

例：1)I began to study English three years ago.(過去試)

　 2)I still study English now.(現(xiàn)在式)

　 3)I have studied English since three years ago.

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 現(xiàn)在時(shí)

▲　　 牢記：表繼續(xù)的動(dòng)詞

have known 已經(jīng)認(rèn)識(shí)了　　　 have studied　 已經(jīng)學(xué)習(xí)了

have worked ； have been to； have used ；have taught ；have stayed;

have wanted to; have lived

▲　　 B→常用的時(shí)間狀語(yǔ)

表示繼續(xù)的現(xiàn)在完成時(shí)，常和下列時(shí)間狀語(yǔ)連用

for+時(shí)間　 since+過去某時(shí)　 all this week　

often　　 today　　 recently　　 all day

up to now　 直到現(xiàn)在　 so far 到目前為止

lately　　 always　　 till/until now　

in the past years

these days

this　 week

during the past (years、month)

1、概述

例：1)繼續(xù) He has been sick since last week.

2) 經(jīng)驗(yàn) I have visited Tokyo twice.

　　　　 Have you ever been to Hawaii?

3) 完成 I have just finished my homework.

　　　　 Has he finished his work yet?

4) 結(jié)果 My father has become a lawyer.

　　　　 I have lost my dictionary.

下面分別闡述其用法

A→現(xiàn)在完成時(shí)的肯定句

句型：主語(yǔ)(I、we、you第三人稱復(fù)數(shù))+have+過去分詞

　　　 主語(yǔ)(第三人稱單數(shù))+has+過去分詞

例：1)I have been busy all the day.

2) My father has read today’s paper.

3) 　I have just written the letter.

B→現(xiàn)在完成時(shí)的否定句

句型：主語(yǔ) + have/has + not + 過去分詞

例：1)The concert hasn’t/has not started yet.

2)They haven’t gotten to London yet.

C→現(xiàn)在完成時(shí)的一般疑問句

例：1)Has the concert started?

2) Have you friend your homework?

D→現(xiàn)在完成時(shí)的特殊疑問句，分兩種情況

a.　　 疑問句詞作主語(yǔ)時(shí)

句型：疑問句(主語(yǔ))+have/has+過去分詞+……？

例：1)Who has/have bought these apples?

　 2)Who has made her so sad?

B→疑問詞作主語(yǔ)以外的成分時(shí)

句型：疑問詞+have/has+主語(yǔ)+過去分詞+……？

例：1)How long have you live here?

2)How many times have you been to Spain?

19．(12分)呋喃丙胺是一種高效麻醉劑，在臨床上被廣泛使用，也可用于治療心律失常。由呋喃甲醛合成呋喃丙胺的流程如下：

已知：

試回答下列問題：

⑴物質(zhì)A的結(jié)構(gòu)簡(jiǎn)式是　　 _________________________　 ；

反應(yīng)①~⑤中屬于取代反應(yīng)的有　　　 (填序號(hào))。

⑵呋喃甲醛中碳原子的雜化方式為　　　 ，分子中共平面的碳原子最多有　　　 個(gè)。

⑶呋喃丙烯酸的同分異構(gòu)體中屬于醛類且含有酚羥基的結(jié)構(gòu)共有　　　　　 種。

⑷反應(yīng)③的化學(xué)方程式為　　　　　　　　　　　　　　　　　　　　　　 。

⑸反應(yīng)⑤的化學(xué)方程式為　　　　　　　　　　　　 　　　　　　　　　　。