完成句子 （根据课文内容填空，每空一词，每空一分，共15分）
小题1:            my sister        first had the idea to cycle along the entire Mekong River from where it begins to where it ends. 首先想到要骑车沿整个湄公河从源头到终点旅行的是我的姐姐。
小题2:When I told her the air would                                        and it would be very cold， she said it would be an interesting experience.当我告诉她那里空气稀薄，呼吸困难而且天气很冷时，她却说这是一次有趣的经历。
小题3:Our legs were         heavy and cold         they felt like blocks of ice
我们的腿又沉又冷，感觉就像大冰块。
小题4:Only then                                 to answer violence with violence
只有到这个时候，我们才决定用暴力反抗暴力。
小题5:I can well remember that there was                             a deep blue sky， the song of the birds，moonlight and flowers could never have kept me spellbound 
我记得曾经有一段时期深蓝色的天空，鸟的歌唱，月光和花从来没让我着迷。