【SAT文法】改进句子题：No one knows why the carved……

题目

【SAT文法】改进句子题：No one knows why the carved……
No one knows why the carved stone head in a column in Istanbul is upside down,but (they belive it that it was placed that way deliberately.)
替换括号中的
A.it is believed to have been placed that way deliberately
B.placing it that way is believed to be deliberately done.
但B为什么不对?

答案

在英语中it is said/supposed/thought/believed/reported/expected...that...句型经常可以换成从句中的主语+is said/supposed/thought/believed/reported/expected/considered...to do的形式,如果that句子的谓语动词已经发生,to do要换成to have done;如果that中的谓语动词正在发生,to do中的do用be doing;其他的基本用to do 就行.这些结果基本翻译为据说/据报道/人们相信/人们料想某人.如：据说他昨天离开了这家工厂了.It is said that he left the factory yesterday.=He(that句中的主语) is said to have left(that后的动作已经发生,所以这里用to have done的形式,) the factory yesterday.
据报道他正在美国读书.It is reported that he is studying in UAS now.=He is repprted to be studying in USA now.
人们相信他会成功的.It is believed that he will make it some day.=He is believed to make it some day.
所以本句话中替换括号中的句子可以换为It is believed that it was placed.,然后就可以换成it（that句中的主语）is believed to have been placed（that后的谓语动作已经发生,所以不定式后用完成式的形式）.故最佳答案为A
能明白吗?