Please help! 20 points and I will mark correct answer brainliest! which statement describes the limitations of the geocentric model?

a. the model cannot explain why planets appear to go backward and make loops in the sky
b. the model cannot explain why planets appear to move the same way across the sky
c. the model cannot explain why the sun and other stars appear to go backward and make loops in the sky
d. the model cannot explain why the sun and other stars appear to move the same way across the sky

A-4.60 μc charge is moving at a constant speed of 6.80×105 m/s in the +x−direction relative to a reference frame. at the instant when the point charge is at the origin, what is the magnetic-field vector it produces at the following points.

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.

What’s #16 asking and how do i solve it?