The house is comfortable to live in.为什么不用被动?

The house is comfortable to live in.为什么不用被动?
The house is comfortable to live in.为什么不用被动?

The house is comfortable to live in.为什么不用被动?
(一) 不定式主动形式表被动意义
1 . 当不定式用在作表语的形容词后,在句中作状语,而句中的主语又是不定式的逻辑宾语时,通常用不定式主动形式表示被动意义.如上述句1句2.能带主动语态的不定式而表达被动意义的形容词常见的有：easy、difficult、heavy、hard、nice、bitter、dangerous、light、interesting、important、expensive、fit、comfortable、pleasant、impossible等.其句型为S + link v + adj . + infinitive ( 主动语态 ) ,类似这种貌似主动实为被动的系表结构的又如以下例句.
Habits are easy to make but hard to break . ( Habits是to make、to break的逻辑宾语 ) .
The water is fit to drink .
The picture is pleasant to look at .
2 . 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.例如：
Mathilde only has a small cold room to live in . ( Mathilde是to live in的逻辑主语 )
He bought some magazines to read . ( He是to read的逻辑主语 )
3 . 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.例如：
Mother always gives her little daughter some picture books to read . ( Her little daughter是to read的逻辑主语 )
The teacher gave the students some paper to write on . ( The students是to write on的逻辑主语 )
4 . 当不定式所修饰的名词或代词,是“there be…. ”结构句中的主语时 ( 此处用主动或被动式,一般说来无意义上的不同 ) .例如：
There are many problems to work out . ( to be worked out )
(二) 在动词want、need、require等后面常用动名词表示被动含义,等于不定式的被动形式.再如：
The bike needs ( wants ) repairing ( = to be repaired ) . 自行车需要修理了.
(三) worth后跟动名词主动形式表示被动,但是不跟不定式的被动.再如：
This novel is well worth reading.这本小说很值得阅读.
(四) 有些动词不及物动词,只有主动形式,常视为主动表被动.如：
1 . take place、happen、break out等.
A big fire happened / took place / broke out last night .
2 . 感官动词 ( taste ; feel ; smell ; sound ; look ) 用主动形式表示被意思.请看：
How sweet the music sounds !
Good medicine tastes bitter to the mouth .
3 . write、read、sell、keep、prove、weigh、number、drink、wear、pay、wash、open常用主动形式表被动意义.请看下面句子：
The book sells well . ( 这本书销路很好. )
The door will not open . ( 这扇门就是打不开. )
This dress washes better . ( 这衣服较好洗. )
The sign reads as follows . ( 这牌子告示如下. )