Learning about Language
二、用法 1．表示被动的动作发生在说话之前，并强调对现在造成的 影响或结果。如： The door has been locked. 门被锁上了。(
并可能继续持续下去，常与 for 或 since 引导的时间状语连用，
或用于“How long...？”问句中。如： They have been told about it for many times.
How long has the machine been used?
这机器用了有多久了？ 注意：(1)由 finish, buy, start, begin, post, return, borrow, join,
marry, open 等词构成的现在完成时的被动语态不能直接与表示 一段时间的短语如 for four days, how long 等连用，需要改换动 词或时态。如：
How long has this book been bought？(×) How long has this book been had？(√)
When was this book bought？(√) 这本书买了多久了？
since 或 for 引导的时间状语连用。如： No books have been bought since last week. 自上周以来，没有人来买过书。 (2)动词短语是一个不可分割的整体，在被动结构中要保持 完整性，不可省略动词短语中的介词或副词。如：
The orphan has been well looked after. 这个孤儿一直受到很好的照顾。
一、用所给单词或短语的适当形式填空 hasn't been decided 1．Who will be sent there ____________________ (not decide)
2 ． So far, almost two-thirds of this book ________________ has been learnt (learn) in all.
has been closed 3．It is said that the bridge ____________________ (close) for
repairs for months. has been enlarged 4．Our school area ___________________ (enlarge) for many
times in the last few years.
5 ．This is one of the farthest places that have been explored ________________ (explore) so far in that country. has been made 6 ． In recent years, much progress ____________________ (make) as a result of his efforts. 7 ． The government has proved that most of the buildings have been destroyed ____________________ (destroy), leaving many people dead or injured. have been typed 8 ．By now, all the letters ____________________ (type) for your convenience.
二、完成句子 1 ． Since last year, many art companies' old mechanism __________________________ ( 被转变) into a new one suitable has been changed/transformed for the market.
2．Since Earth Hour first began in Sydney in 2007, so far, the
has been carried out project ____________________ (被开展) in more than 4,000 cities around the world. 3．In recent years, with the improvement in people's life, most have been replaced of fans ____________________ (被取代) by air-conditioners. have been killed 4．By now, thousands of people ____________________ (遇 难) in the terrible earthquake, leaving tens of thousands homeless.