题目

若a＞0，b＞0，则不等式－b＜＜a等价于( )． A．－＜x＜0或0＜x＜                    B．－＜x＜ C．x＜－或x＞                          D．x＜－或x＞ 答案：D 解析 由题意知a＞0，b＞0，x≠0， (1)当x＞0时，－b＜＜a⇔x＞； (2)当x＜0时，－b＜＜a⇔x＜－. 综上所述，不等式－b＜＜a⇔x＜－或x＞.完成句子【1】实验之后，这棵植物的高度是原来的四倍。After the experiment, the plant is four times the _________ __________ what it was before.【2】感谢你帮我走出了困境。I __________ you _________ me out of the whole trouble.【3】看他生气的脸，我们保证绝不再提及那件事了。Seeing his angry face, we promised never to ______ ______ the matter again.【4】虽然物理永远不会是我最喜欢的课，但我认为有陈老师教，我会考的很好。Physics will never be my favourite lesson, but I think that I’ll do well in the exam _________ Mrs Chen __________ me.【5】住在这儿我感到很幸运。I feel very ____________ ______________ here.