He __ the display for several minutes before re-entering his shop.
a. was gazing at b. gazed at c.had gazed at d.had been gazing at
这道题目的选项 had gazed at 和 had been gazing at 分别错在什么地方?for several minutes 表示已经盯着看了一段时间了,为何用gazed at?
友情提示 mikee 网友:
你的三个例句，本身没错。但，语境则是表语从句或宾语从句，这都要遭到主句时态的制约，才用过去完成时的，说明从句的动作早于主句发生，这与 before 没关系。我觉得，before doing... 这个介词短语，跟 before ten oclock yesterday 没不同，是一个表达“过去时间点位” 的词组。
The only reasonable conclusion was that theyhad waited hours before decidingtheyd have to get rid of her.
--摘自小说The Marshal at the Villa Torrini
When the deputy asked whyhe had waited hours before callingpolice, the 19-year-old said he had been trying to figure out the identity of the thief.
--摘自 英语网站 pjstar
In his interview, Dr. Wang said that he had misdiagnosed his symptoms as those of flu, and that hehad waited days before checkinghimself into a hospital.
--摘自 英语网站 纽约时报
针对此题，我谈谈个人的怎么看：
He _______ the display for several minutes before re-entering his shop.
a. was gazing at b. gazed at c.had gazed at d.had been gazing at
1. 毫无疑问，此题正确答案为： B.gazed at
2.for several minutes 表示一个动作持续了这期间后结束。所以排除“进行体”，也就是排除 A。简单地说，目前进行时和过去进行时，都不可以跟时间段连用。道理就是，跟了时间段，就意味着动作结束了，违背了进行时的基本定义。
3. “过去完成时” 的参照物，应该有“上文”，本题是个单选题，一定没上文。第二，看其他语境，仅仅before re-entering his shop 是不足以支撑用“过去完成时” 的。除非改为一个时间从句，加上另外的一个谓语动词，作为“参照物”。前面说过，before doing... 这个介词短语，跟 before ten oclock yesterday 没本质不同，是一个表达“过去时间点位” 的词组。
4. 既然过去完成时都不需要，那样，过去完成进行时，就更不可以用了。
