已知：a，b互为相反数，cd互为倒数，|x|=3，则4cd﹣a﹣b+x=（）．_爱下问搜题

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问题填空题

已知：a，b互为相反数，cd互为倒数，|x|=3，则4cd﹣a﹣b+x=（）．

答案

1或7

选择题

He was hoping to go abroad; but his parents __________ that they won’t support him unless he can borrow money from the bank.

A．were deciding

B．have decided

C．decided

D．will decide

问答题简答题

试述慢性阻塞性肺部疾病(COPD)发生气流阻塞的机制。