---How long have you your penfriend?---For five days. I received it last Sunday.A. heard

问题补充：

---How long have you your penfriend?

---For five days. I received it last Sunday.

A. heard from

B. received the letter from

C. heard of

D. had the letter from

答案：

A. heard from

B. received the letter from

C. heard of

(答案→)D. had the letter from

解析：句意：你收到你笔友的信多久啦？五天了。我是在上个星期天收到的。How long是对一段时间的提问，句中谓语动词必须是延续性动词，但heard、received都是结束性动词，所以选D。