i did not understood the problem until he had explained it这句

i did not understood the problem until he had explained it这句 i did not understood the problem until he had explained it. i did not understand the problem until he had explained it.我 请问一个英语问题：I did not understand the problem.He explained it 两句 i did not realize my mistake until he explained it to me改成倒装 英语翻译1.i explained the problem to him,but he did not believe I _____ the prolem until he explaind it.A.understood B.did n It was not until I had read your letter that I understood th once he explained a maths problem to me u____ i understood i 翻译Not until most of the people had left the airport did he s Not until yesterday did I notice it. I did not know what had happened until she told me about it.