题目

“Could you see the whites of their eyes?” said the man, who was seated on a soap box.“Nothing of the kind,” replied old Henry warmly. “Just a lot of figures running towards us, and I let go at where there appeared to be most. Bang!”“Mr. Fleming, ” said the grocer — his respectful voice expressed somehow the old man’s exact social weight — “Mr. Fleming, you never were frightened much in those battles, were you?”The veteran (老兵) looked down and smiled. Observing his manner, the entire group laughed a little. “Well, I guess I was,” he answered finally, “Pretty 天山山脉是亚洲内陆中部东西向的一条大山脉，把新疆分为北疆和南疆两大气候区。北疆和天山山区（北疆）冬季漫长而寒冷，是我国积雪最丰富的三大区域之一，也是两个寒潮高频区之一。下图为北疆冬季低温日阈值空间分布图（单位：℃）。读图，回答下列问题。注：阈的意思是界限阈值，又叫临界值。1.北疆降雪的水汽主要源自（ ）A. 北冰洋 B. 大西洋 C. 印度洋 D. 太平洋2.冬季低温日阈值的空间分布特点是（ ）A. 东高西低 B. 西高东低 C. 北高南低 D. 自东北向西南升高3.图中气温最低阈值区域形成的主要原因是（ ）A. 纬度位置 B. 海陆位置 C. 地形 D. 洋流