2015年9月13日托福写作考试真题回忆及解析

Why toucan evolved a bill

1 weapon against predators;

1 cannot function as weapon: it is made of hollow hones filled with air, so it is the thin and lightweight; or else it cannot fly. If it is used as weapon, it will be easily damaged in activities like jabbing.

2 color and shape to hide from predators

2 they have to call out to each other in order to use the color and shape to blend into surroundings. If they do this, they are going to draw attention from predators

3 get rid of excess body heat

3 Health toucan do not use their bills: they need bill to get rid of heat in the daytime but at night when the temperature is lower, they then need to retain body heat.