22 Although this problem（ ）many times,it was too difficult（ ）A has been explained；to understandB was explained；to be understoodC is being explained；to be understoodD had been explained；to understand1 把题目和选项都翻译一遍2

来源：学生作业帮助网 编辑：作业帮 时间：2024/05/14 06:27:08

22 Although this problem（ ）many times,it was too difficult（ ）A has been explained；to understandB was explained；to be understoodC is being explained；to be understoodD had been explained；to understand1 把题目和选项都翻译一遍2
22 Although this problem（ ）many times,it was too difficult（ ）
A has been explained；to understand
B was explained；to be understood
C is being explained；to be understood
D had been explained；to understand
1 把题目和选项都翻译一遍
2 说出正确选项
3 解释为什么.越详细越好.

22 Although this problem（ ）many times,it was too difficult（ ）A has been explained；to understandB was explained；to be understoodC is being explained；to be understoodD had been explained；to understand1 把题目和选项都翻译一遍2
主句过去时,many times用完成时,所以用过去完成时
English is easy/ hard/ difficult to learn.语法要求不能变动,所以D

C 尽管这个问题已被解释过很多次，但他还是很难理解。
后面句子用的是过去式 说明解释过也是在过去 且对结果造成影响 故用过去完成时

翻译：这个问题太难了以至于我不能明白。
答案A
句子中出现了though although等单词时，是现在完成时的标志，答案A符合，再加上too....to句型to后边加动词原型

This room requires Camfrog Pro to open video.怎么回事? Although you can not read this sentence, This room requires Camfrog Pro to chat.用camfrog聊天为什么显示：this room requires camfrog pro to chat although 什么意思Although you can not read this sentence, Although money is not everything in this worl 英文翻译To open this file,please update your Guitar Pro software是什么意思 premiere pro cs4出现licensing for this product has expired怎么办 This is only a pro forma invoice.谁给我翻译一下? pro choice PRO是什么意思 PRO 是什么意思? pro-democracy Pro-Gadhafi I can do this thing stand on my head,although I won't do this.英语翻译 英语翻译although this doesn't mean that opinions regarding this subject do not differ. 英译中,Take this job and love it:Ten ways to shake job stress In his classic,The Pro didn't attend the lecture by Pro.Jack.I would but I have been washing all this morning的翻译