1. 主句为现在完成时，其宾语从句可以为一般将来时吗？

【答】完全可以。

We have been informed that the plane will arrive an hour late. 我们被告知飞机将晚一个小时到达。

I have heard that he is going to retire.  我已听说他准备退休了。

在含有宾语从句的复合句中，主句的时态决定着从句时态。如果主句谓语动词的时态属于现在时间范畴（含有“现在”二字的时态），宾语从句的时态则不受限制，只要句意需要。

以下句子都可以说：   

I have heard that Tom went to London.

I have heard that Tom has gone to London.

I have heard that Tom goes to London once a month.

I have heard that Tom will go to London.

I have heard that Tom is going to London.

I have heard that Tom had gone to London before you returned.

上述句子中，把have heard改为一般现在时hear，则完全可以。

2. 主句为过去完成时，其宾语从句可以为过去将来时吗？

【答】完全可以。

He didn’t come that day. He had told me that he would attend an important meeting. 那天他没有来。他告诉我他将参加一个重要会议。

They prepared their gifts for Joseph's arrival at noon, because they had heard that they would eat there. 他们为约瑟中午到来准备了礼物，因为他们听说他们要在那里吃饭。

第三个句子has gone发生在现在之前还是have heard之前？

【答】has gone发生have heard之前。又如：

The doctor has told me that she has quite recovered from her illness.  医生告诉我她已完全病愈。

I have heard that he has been married before.  我听说他以前结过婚。