The diagram below shows the positions of Earth, Sun, and moon during two types of tides. The gravitational forces due to the sun and the moon

A. amplify each other’s effect during Tide 2 and cancel each other’s effect during Tide 1
B. amplify each other’s effect during Tide 1 and cancel each other’s effect during Tide 2
C. do not affect high and low tides during Tide 1
D. do not affect high and low tides during Tide 2

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. this is an example of speciation.

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Which of the follow describes a disadvantage secondary sources have compared to primary sources?