Nick and Bart climbed a 2000-m mountain. Nick took a 3-km trail, and Bart took a 6-km trail. If Nick and Bart weigh the same, their packs weigh the same, and they walk the same speed, why did Nick have a harder climb?

What is the primary goal of human communities?

How do living things obtain phosphorus

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.