题文

答案

据专家权威分析，试题“______ very important and convenient for us ______ a mobile ..”主要考查你对  不定式，it 的用法  等考点的理解。关于这些考点的“档案”如下：

不定式it 的用法

考点名称：不定式

• 动词不定式：
  指由to加上动词原形（而且只能是动词原形）所构成的一种非限定性动词，但在有些情况下to可以省略。
  动词不定式在语法功能上可作主语、宾语、宾语补足语、表语、定语和状语。

• 动词不定式可以作以上各种成分，但它毕竟是动词，所以有动词的属性。
  动词不定式及其短语还可以有自己的宾语、状语，虽然动词不定式在语法上没有表面上的直接主语，但它表达的意义是动作，这一动作一定由使动者发出。
  这一使动者我们称之为逻辑主语，其形式如下：
  

  时态	主动形式	被动形式
  一般式	(not) to do	(not) to be done
  完成式	(not) to have done	(not) to have been done
  进行式	(not) to be doing
  完成进行式	(not) to have been doing

• 不定式的用法:
  1、不定式作主语
  例如：To remember this is very important.
  注意：为了避免头重脚轻，在许多情况下，通常都将作主语的不定式置于句子后部，而在句首主语位置使用形式主语it。
  例如：It is very important to remember this.
  2、不定式作表语
  例如：He seems to be ill.
  注意：不定式作表语主要有三种情况，一是用于seem, appear, prove等系动词之后的不 定式（尤其是to be），
  二是像My job is to sweep the floor. 这样的主语与表语“等价”的情形，
  三是表示想法、约定、义务、命令、可能性、命运等，如： 
  You are to come when I call.
  3、不定式作宾语
  例如：I can not afford to buy a car.
  注意：
  ①不定式不仅用作动词的宾语，还可用作个别介词（but, except）的宾语。
  例如：I had no choice but to wait.
  ②当作宾语的不定式后跟有宾语补足语时，通常要用形式宾语it代替不定式，并将真正的宾语不定式置于宾语补足语之后
  例如：I find it difficult to learn Japanese well.
  4、不定式作宾语补足语
  例如：Who taught you to drive?
  5、不定式作定语
  例如：I have a question to ask you.
  注意：有的名词（如way, chance, right等）后用作不定式可换成of doing sth.
  如：It is the best way to do (of doing) it.
  但是以下名词后接不定式作定语时通常不能换成of doing sth.
  attempt  courage  decision  effort  fortune  failure  invitation  wish
  6、不定式作状语
  例如：I went to France to learn French.

考点名称：it 的用法

• “It”用法及其句型和固定搭配，是英语语法的重点、难点，又是近几年考试的热点，因此在复习中应给予足够的重视。

• It 句型归纳：
  1． It is ＋adj．(＋for sb．／sth．) ＋ to do sth．
  用于此句型的形容词有：easy， hard， difficult，possible， important， impossible， necessary， good， bad， exciting， interesting， surprising等。如：
   It is necessary to change your job．
   It was very hard for them to walk such a long way in the snow．
  2．It is ＋n．(＋for sb．／sth．) ＋ to do sth．
  用于此句型的名词有： pity, shame, pleasure, one’s duty, one’s job, fun, joy, good manners, bad manners等。如：
   It is a pity for you to have missed such a wonderful play．
   It is bad manners for the young to take up the seats for the old．
  3．It is ＋adj．＋of sb．＋to do sth．
  此句型中的形容词主要描述某人的品德、特征。能用于该句型的形容词有： kind, nice, wise,
  silly, polite, impolite, friendly, foolish, clever等。如：
   How silly it was of you to give up such a good chance！
   It is friendly of the family to try to make me feel at home in their house．
  4．It is ＋adj．（＋n．）＋doing sth．
  此句型中的形容词和名词常见的有：no／little use, no／much good, useless等。如：
   It’s no use crying over spilt milk．
  5．It takes sb．＋一段时间＋to do sth． 表示“做某事花费某人多长时间”。如：
  It took us half an hour to ride to the town by the sea．
  6．It is ＋及物动词的过去分词＋that从句
  此句型中常见的及物动词的过去分词有：said, told, known, reported, recorded, thought, believed, considered等。如：
  It is reported that the Russian President will visit China next week．
  7．It ＋不及物动词＋that从句
  此句型中不及物动词常见的有：seem， happen， appear， matter等。如：
   It seems that there will be a heavy snow tomorrow．
   It happened that I met my good friends in the museum yesterday．
  8．强调句型：It is＋被强调部分＋that／who从句
  在使用强调句型时要注意，指人时可以用who或that，其它情况一律用that。如：
   It was under the bed that my brother hid the ball this morning．
   It is Mr Bell who／that often comes and looks after the old man．
  9．It is／has been＋一段时间＋since从句。如：
  It is ／has been three years since we saw each other last．
  10．It is (high) time that sb． did sth．
  该句型表示“某人现在该做某事了”，从句常用过去时（虚拟语气）说明现在应该做的事情。如：
   It’s six o’clock．It is high time that we went home now．
  
  It 常用的固定搭配：
  1. make it
  （1）在口语当中相当于succeed，表示：成功、做到、说定、赶上、及时到达
  例  It's hard to make it to the top in show business.
  （2）在口语中相当于fix the date for，表示“约定好时间”
  例  —Shall we meet next week？
  —OK. We just make it next Saturday.
  2. as it is
  （1）相当于in fact，in reality表示“事实上，实际情况是……”
  例  We had planed to finish the task today，but as it is we probably won't finish it until next week.
  （2）相当于方式状语从句，表示“照原样”
  例  Leave the table as it is.
  3. as it were
  相当于as one might say，that is to say，表示“也就是说，可以说，换句话说”
  例  He is，as it were，a modern Sherlock Holmes.
  4. if it weren't for…/if it hadn't been for…
  用来引导虚拟语气，相当于without，or but for，表示“如果不是……，要不是……”
  例  If it weren't for Tom，I wouldn't be alive today.