Question

had been和have been有什么区别？请举例

Answer 1

had been是过去完成时结构：had+动词过去分词：表示两个事件中一个发生在前，或者说是表示较早的过去。
After they had entered the house,they went into the dining room.
他们进到屋里后，走进了饭厅。
have been是现在完成时结构：have/has+动词过去分词：单数第三人称用has，其余用have。表示在过去不确定的时间里发生的并与现在有着某种联系的动作；或者表示开始于过去并持续到现在的动作。
I've just had a cup. 我刚喝了一杯。此处had为动词have（喝）的过去分词

Answer 2

更正：
had been是用在过去完成时，是指过去的过去，I had been in USA for 3 years since you left.

have been是用在现在完成时，是指到现在为止，I have been in USA for 3 years .

Answer 3

had been是用在过去完成时，是指过去的过去，I had been in USA for 3 years since you left.

have been是用在现在完成时，是指到现在为止，I have been in USA for 3 years .

Answer 4

时态不一样