A large rift valley can be found along the east coast of Africa. It has been slowly widening over time, and it is now wide enough to contain many large lakes. Which of these best explains the slow widening of this rift valley over time?
Group of answer choices

Earth's rotation

wind and water erosion

the Moon's gravitational pull

lithospheric plate movement

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent

The sum of the oxidation numbers in a neutral compound is always