是現(xiàn)在完成時(shí)。Having been done是現(xiàn)在分詞的完成時(shí)的被動(dòng)語態(tài)，用的時(shí)候常常會(huì)出現(xiàn)一個(gè)段時(shí)間狀語。having been done強(qiáng)調(diào)動(dòng)作發(fā)生在謂語動(dòng)詞表示的動(dòng)作之前。

Having been done一般強(qiáng)調(diào)被動(dòng)的動(dòng)作，而且該動(dòng)作必須和主句動(dòng)作之間有著明顯的時(shí)間/邏輯上的先后/因果關(guān)系，且隱含having been done的動(dòng)作不會(huì)再進(jìn)行的意味。

例如：Having been kept in the fridge for two hours, the food has gone bad。此題強(qiáng)調(diào)先有“be kept in the fridge”，才導(dǎo)致了后面的“go bad”。 前后動(dòng)詞有明顯的先后/因果關(guān)系，且隱含了“這食物不會(huì)再放在冰箱里保存”的含義了。

造句示例：

1、Having been well tended for half a year, my granny became far better.

被精心照料半年后，我奶奶的情況好多了。

2、In conclusion, the work having been done and being to be perfected are put forward.

本文最后總結(jié)了完成的工作，以及日后可以改進(jìn)和完善的地方。

3、There are two kinds of efforts having been done to solve the problem: one is using novel searching methods, such as Genetic algorithm, Simulated Annealing Algorithm etc;

解決問題的辦法有兩種：一是用新穎的搜索方法，如遺傳算法，模擬退火算法等；