D. 修辞的需要，为了使句子更加简练、匀称
He appeared on the stage and was warmly
applauded by the audience. 他出现在舞台上，受到了观众的热烈鼓掌。
The old professor gave a lecture on
American history and was well received. 这位老教授作了一个有关美国历史的讲座，受到大家的热烈欢迎。
I was shown round the school campus by
Sean, who had entered the school just a year before. 肖恩带我参观了校园，他去年刚进这所学校。
E. 为了表示委婉或礼貌，避免提及动作执行者或说话者自己
You've been told many times not to make
the same mistake. 你已被多次告知不要犯同样的错误。
Everybody is expected to obey the
following rules. 希望大家遵守以下规定。
The control room may not be entered
without permission. 非经许可，勿入控制室。
F. 科技文献中为了客观地描述事情及其过程
The film is coated with light-sensitive
chemicals, which are changed by the different shades and colours of light. 胶卷上涂了一层感光的化学物质，这些物质因光的不同色度与颜色而改变。
G. 新闻报道中为了体现新闻的客观性
The west-east gas pipeline project was
kicked off on July 4, a big event in the nation's west development campaign. 西气东输工程7月4日全线开工，这是国家西部大开发战略的一件大事。
H．有些动词习惯上常用被动语态
He was born in this city. 他出生在这个城市。
The school is situated in the suburbs. 这所学校位于郊外。
注意：
被动语态中的by短语通常可以省去。但如果by短语是句子的重点所在，或者没有by短语全句的意思不完整时，则要保留by短语。
The vegetables didn't taste very good.
They had been cooked too long. 蔬菜的味道不好，烧的时间太长了。（不需要动作的执行者）
He arrived at the airport, where he was
met by his friend. 他到达了机场并受到朋友的迎接。（没有by
his friend，句子的意思不完整）
Everybody was cast down by such news as
that. 大家都被那种消息搞得很沮丧。（需要by短语）
第二章 被动语态（二）
三、主动语态变被动语态
中国人的思维的着眼点在动作的施动者，英美人思维的着眼点在动作的承受者。
中国人常这样说：I
expect you to be there on time. 我希望你准时到那里。
英美人常这样说：You
are expected to be there on time. 希望你准时到那里。
这就是英语中被动语态的使用比汉语中多的原因。由于英语句子的主动语态结构不同，因而变成被动语态的方式也各不相同。
A. 主语 + 谓语 + 宾语
“主语 + 谓语 + 宾语”结构中只有一个宾语，变为被动语态时，将宾语变为主语：
They will discuss the plan at the
meeting. 他们将在会议上讨论这个问题。
-- The plan will be discussed at the
meeting. 这个问题将在会议上讨论。
In the past the king possessed great
wealth. 过去国王拥有巨大的财富。
n In the past great wealth was
possessed by the king. 过去，巨大的财富为国王所拥有。
B. 主语+谓语+间接宾语+直接宾语
在这个句型中，谓语动词跟有两个宾语。变成被动语态时，一般将通常指人的间接宾语转化成主语，但有时也可将指物的间接宾语转化成主语：
We gave the student some books. 我们给了这个学生几本书。
-- The student was given some books. 这个学生被给了几本书。
-- Some books were given to the
student. 几本书被给了这个学生。
His father bought him a computer last
week. 上周他父亲给他买了一台电脑。
-- He was bought a computer by his
father last week. 上周他父亲给他买了一台电脑。
-- A computer was bought for him by his
father last week. 上周他父亲给他买了一台电脑。
注意：用直接宾语作被动语态的主语时，通常要在间接宾语前加上适当的介词(如to,
for, of等)，以加强间接宾语的语气。
They awarded him the Nobel Prize. 他们授予他诺贝尔奖。
-- The Nobel Prize was awarded（to）him.
诺贝尔奖被授予给他。
The host had caught us some fish. 主人给我们捉了一些鱼。
n Some fish had been caught for us
by the host. 主人给我们捉了一些鱼。（for不可省）
n
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