以下是引用yangtingno1在2004-9-10 16:53:00的发言: Q21:Which of the following most logically completes the passage?
Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators. In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.
B. large moths are proportionally much more common in warm climates than in cool climates
1.气温与体温match -> 有效飞行; 2.当气温 << 体温 -> 不能有效飞行,且易被捕食;
3.大娥比小娥飞得快 -> 大娥逃生能力强;
4.大娥的最佳体温 >> 小娥的;
-> 大娥需要相应的比较高的气温环境,以保证他们的有效飞行,所以推出B选项,大娥通常在暖温气候地区。 |