21. Art historians are using a process known as infraredscanning in analyzing the Mona Lisa to determine if it has been altered since completion and if Leonardo da Vinci first sketched the figure in black,as done by many artists of the time.
(C) whether it has been altered sincecompletion and whether Leonardo da Vinci first sketched the figure in black, apractice employed
(E) whether it had been altered sincecompletion and whether Leonardo da Vinci first sketched the figure in black, apractice done 答案:c。开始选的c因为从are using看出整个句子的时态应该是现在时,后来觉得两个whether后从句的时态不一致又选了e。 大家帮忙看看,我的问题在哪。谢谢!
[此贴子已经被作者于2004-11-13 12:44:25编辑过] |