has been used to detect gold,这是什么时态?句中的used to 是表示过去常常做某事吗?

问题描述:

has been used to detect gold,这是什么时态?句中的used to 是表示过去常常做某事吗?
A new machine called 'The Revealer' has been invented and it has been used to detect gold which has been buried in the ground.这句中的it has been used to detect gold是什么时态?used to 是表示过去常常做某事的意思吗?has been buried in the ground这句是现在现成时的被动态吗?请详解.
1个回答 分类:英语 2014-10-28

问题解答:

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两者都是现在完成时.has been used to是be used to的现在完成时形式,是“从发明以来一直被用来勘探金矿”的意思,而同样的has been buried in the ground是be buried in the ground的现在完成时形式,就是说“金矿一直被埋在地下”.可以看出两者都是被动语态的现在完成时形式,用法为sth./sb.+has/have+been+done(动词过去分词).现在明白了吗?
 
 
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