现在完成时可后接last night吗?

有读者问这样一句话:

(1)We have already discussed this affair last night.

这里的现在完成时have discussed后接指具体过去时间的状语last night对吗?

我们知道,现在完成时可后接表笼统的过去时间的状语,如:

(2)I have ceased to believe that long ago .

不少语法家们都说long ago在此是一种添补之词,是事后想到的一种说法。但这只限于表笼统的过去时间的状语的说法看来已被突破,现在也可用表具体的过去时间状语了,例(1)中的last night即是一例。再如:

(3)The five-thirty train has been in and gone half an hour ago .

(4)The Chinese team has defeated Serbia and Herzegovina on Monday .

(5)China's procuratorates have made obvious progress last year in handling violations of law by government officials.

请注意这种用作添补之词的时间状语理应置于句末,如上述例(1)、(2)、(3)、(4),但例(5)中的添补词last year却置于句子中间,这不能不说是又一次惯例的突破。