been是什么時(shí)態(tài)的

　　Progress has been particularly disappointing.

　　進(jìn)展一直格外令人失望。

　　Where have you been? We've been looking for you.

　　你上哪兒去了？我們一直在找你。

　　Where have you been? I've been trying to get hold of you all day.

　　你去哪了？我一整天都在找你。