1.plastics ____wide application not only in industry but asl

1.plastics ____wide application not only in industry but aslo in the daily life.
A are found B will be found c find D has been found
为什么不是选择D
2.when a bar of iron attracts other pieces of iron,it ____a magnet,and thus attraction is called mangnetism.
A will be acted B acted as C is acted as D has acted as
为什么选择B.不选择 C
3.____,wood will soon burst into a flame.
A Heating B when heating C being heated D when heated
为什么选择D,不选择C
4.I asked her if she had any rooms to ____
A let B be letted C be letting D have let
为什么选择A,不选择B
易于理解的回答,小女子给高分相谢~
第一题答案是C find

C find 请参阅以下[考查热点2]
B acted as 这里act as是一个词组表示“担当”,“起.作用”
原句意思是“当一个条形铁块吸引其它铁片,它就起一个磁铁的作用,同时这用吸引作用被称为带磁性”
显然这里没有被动意味,故用主动时态.
D when heated=when it is heated 这里是when引导的一个时间状语从句.英语中在时间和条件状语从句中用一般现在时代替一般将来时.故这里用is.进行时态being heated表示动作正在进行即“正在被加热”,而题意是要说明一个条件,即“一旦被加热,木头会很快燃烧起来产生火焰.”
A let 请参阅以下[考查热点9]
主动形式表示被动含义的用法归纳：
主动语态表示被动含义是学习语态的难点,也是高考考查的热点.现归纳如下：
[考查热点1]
感官动词常用作系动词(如taste,feel,smell ,sound,look,smell等),常用主动形式表示被动含义.例如：
How sweet the music sounds!
The flowers smell sweet．
That sounds very reasonable．
[考查热点2]
某些动词如cut,drive,pay,write,read,sell,keep,prove,weigh,number,drink,wear,pay,wash,open,cost,lock,last等常用主动形式表被动含义,这时常和well,easily,perfectly,badly,slowly等方式副词连用,这种用法多用来说明主语的特征、性质或所处的状态等.例如：
The pen writes quite smoothly．
The book sells well.
[考查热点3] 在too…to结构中常用不定式的主动形式表示被动含义.例如：
It's too good a chance to miss．
[考查热点4]
有些及物动词如cook,burn,print,prepare等有时会用进行时态表示被动含义.例如：
The potatoes are cooking．
The dictionary is printing．
[考查热点5]
在“need／want／require+V-ing”及“bear／stand+V-ing”结构中用动名词的主动形式表示被动含义,这时相当于不定式的被动式.例如：
My car needs／wants／requires repairing．＝My car needs／wants／requires to be repaired．
[考查热点6] 在There be句型中,something,anything,nothing等不定代词以及名词之后的不定式往往用主动形式表示被动含义.例如：
There is nothing to do — I'm bored．
There are six letters to write tonight．
[考查热点7] be+to blame／to
seek等结构具有的特点是作表语的不定式与句子的主语有逻辑上的动宾关系,因而用主动形式表被动含义.例如：
A better way is to seek.
Nobody is to blame for the accident．
[考查热点8]
当不定式所修饰的名词或代词是及物动词的直接宾语,而间接宾语是不定式的逻辑主语时,可以用不定式的主动式代替不定式的被动式.例如：
The teacher gave the students some paper to write on．(the students是to write on的逻辑主语) （some paper 是write on的逻辑宾语）
[考查热点9]
当不定式所修饰的名词或代词是动词的宾语,而句子的主语也是不定式的逻辑主语时,可以用不定式的主动式代替不定式的被动式.若不定式与句子主语或宾语不存在逻辑上的主谓关系,只与所修饰的词有动宾关系时,即只有动作的承受者,没有动作的执行者时,不定式应用被动式.例如：
I have six letters to write today．(write的逻辑主语为I)
This letter is to be written today.
We have a house to let.(let 的宾语是 house)
[考查热点10]
在句型“主语+be+形容词+todo”中,当不定式用在作表语的形容词后作状语,而句中的主语又是不定式的逻辑宾语时,通常用不定式的主动形式表示被动含义.这类形容词有：easy,difficult,heavy,hard,nice,bitter,dangerous,light,interesting．important,expensive,fit,comfortable,pleasant,impossible等.例如：
The picture is pleasant to look at．
The chair looks rather hard,but in fact it is very comfortable to sit on．
注意：当不定式中的动词是不及物动词时,要根据需要补充相应的介词.
[考查热点11]一些介词加具有动作意义的名词构成的介词短语常用来表示被动含义.如：on show／on exhibition,on sale,on fire,out of sight,in sight,under construction,in the charge of,in the posses sion of,under repair,under consideration,under development,under discussion等.例如：
The project is under construction．
His car is under repair．
[考查热点12] 有些不及物动词和词组只有主动形式,常视为用主动形式表被动含义.如：take place,happen,break out,belong to,come out,come about,go up,go out,grow up,consist of,add up to,come into being,come into use,give out,come true,run out,turn up等.例如：
His whole school education added up to no more than one year．
The fire also destroyed cars which belonged to people who worked in the building．
[考查热点13] 形容词worth后用V-ing形式表被动,不可接不定式,但可用be worthy to be done或be worthy of being done形式.例如：
These places of interest are well worth visiting．
These places of interest are worthy of being visited．
=These places of interest are worthy to be visited．
=These places of interest are worthy of a visit．
欢迎探讨词法语法问题.