英语时态中只有四个时，现在时、过去时、将来时、过去将来时。现在的过去可以用过去时，也可以用现在完成体表示。但过去的过去则只能用过去完成体表示，没有过去过去时。所以假设我向你讲述我昨天对某人说我去汤姆家时，他正在修自行车。句子是这样的：

I told him that when I had gone to Tom's house, he had been repairing his bike.

这句话不表示说汤姆修自行车一直修到我昨天和某人说话时为止。主句told已经是过去时，前一天就要用过去完成时，如果动作当时正发生未结束就要用进行体，所以用过去完成进行时。

The president was reported to have been flying across the Atlantic.

= It was reported that the president had been flying across the Attantic.

that从句的过去完成时并不是表示飞越大西洋的动作一直持续到记者报道的时候，而是记者报道这个过去时的动作之前的某个时候正在发生的动作。比如这个句子可能表示的意思是，新闻报道说，某个事情发生时，总统正乘飞机飞越大西洋。

所以，你理解成总统一直在飞越大西洋，一直持续到报道的时候。这种理解是错误的。

所以，He said he had been reading a book. 这句话有歧义。可能是他一直在看一本书，在他说话时还没有看完。也可能是在更早的过去的某个时候他当时在看一本书。过去完成时的这种用法，中国英语教学直接忽略了。但新概念英语中有过去完成时的这种用法。

The president was reported to have been flying across the Atlantic.

同意曹老师和刘老师解答

不定式用了完成体，表示不定式动作在谓语动词动作“”之前发生，而且动作一直都处于持续状态。

It was reported that the president had been flying across the Atlantic.

(1)B is reported to have done sth

=(2)It is reported that B have done sth

Tom is reported to have quitted his job.

=It is reported that Tom has quitted his job.

据说汤姆已经辞职了。

(1)B was reported to have done sth

=(2)It was reported that B had done sth

Tom was reported to have quitted his job.

=It was reported that Tom had quitted his job.

据说汤姆已经辞职了。

(1)B is reported to do sth

=(2)It is reported that B will do sth

The temperature is reported to  decline sharply in one or two days.  

=It is reported that the temperature will decline sharply in one or two days.  

据报告近日气温将明显下降.

The South Bend firemen will is reported to strike.  

It is reported that the South Bend firemen will strike. 

据报道南湾的消防队员要罢工.