Why has English changed over time? _____ all languages change and develop when cultures meet and communicate with each other [ ]

You can depend on whatever promise _______ he makes.

依次填入下列横线处的成语，最恰当的一组是（ ）①法国十八世纪伟大的启蒙思想家卢梭的《社会契约论》__________，给当时法国思想界带来全新的气息，这本书后来成为了反映西方传统政治思想的最有影响力的著作之一。②陕北民歌《山丹丹开花红艳艳》描述了红军长征胜利抵达陕北时，正逢满山的山丹丹花开的美丽情景，歌曲旋律优美，而演唱者阿宝的嗓音__________，更让听者印象深刻。③一位抗战老兵在接受记者采访时回忆说：“当时只听到一声__________般的巨响，身旁火光冲天，前方的战友永远的倒在了血泊中，而我也身受重伤”，说完他黯然。

Mary is giving me English lessons__________my teaching her Chinese.

28My English teacher has given me so much help that I really want to do something for him ______