Only after he had spent several nights working on the math p

it was only after he had spent several nights digging around 英语选词填空（3）The 28-year-old had spent six years working nights He thought he had d______ working out the math problem. I had been working on math for the whole afternoon and the n only after they had discussed the matter for several hours _ he spent a whole night () the desk for the math exam.A.on,B. After several years’ hard working,he achieves success/his am Only after he had spoken out the word did he realize he had he is working on the math project this______week.A.all B.who 初二一道英语单项选择He is working on the math project this （ ）weekA.al I spent half an hour working out the math problem.这里的working Only after he had an operation on his heart _____ he should