A-A+
A．The sun is in the same direction.B．They can
问题详情
A．The sun is in the same direction.
B．They can see the compass.
C．They have made the sign on the way.
D．They have the instinct to tell the direction.
参考答案
正确答案：D
解析：题干中询问鸟类每年都能找到同样的地方的原因。文章中提及鸟类像海员一样利用太阳、月亮、星星来判断方向，而且它们体内像装了指南针一样通过地球磁场来判断方向。根据此信息，推测出鸟类的这个特性来自本性。故答案为D。
