The valves prevent the backward flow of blood.
The correct Answer is D. a decrease in the cost to farmerd who rely on momocultures
The correct answer is C: Canyon
I think it is d) all of the above
For the answer to the question above, <span>A total eclipse is only </span>visible<span> from a narrow strip (about 150 km wide) of the Earth's surface at any one time. From the areas outside this narrow strip, the Sun appears to be only partially covered and a partial eclipse is seen. A partial eclipse will also occur if the Sun, Moon, and Earth are not precisely lined up. The eclipse cannot be total unless the center of the Moon's shadow is able to strike the Earth. The eclipse type that occurs when the Moon is at its farthest distance from the Earth is an annular eclipse. The Moon then appears too small to completely block out the disk of the Sun.</span>
