<span>This is the practice of planting the soil in steps while on a steep slope and this helps reduce runoff which reduces erosion.</span>
<span>A fossil leaf that is made only of carbon preserved between two rock layers is called carbon film fossil.
</span>Characteristic of the carbon film fossils is that they are primarily composed of carbon. The fossil leaf has usually lost <span>internal components (cell walls and internal cell structures ).</span>
I think the correct answer would be the first option. The best method to use in order to measure the distance of star would be to calculate the variations in the position of the star due to movement of Earth in its orbit. The doppler shift which is what is being described in the last three options does not calculate the distance rather it calculates the relative velocity. The method used in measuring the distance was introduced by Edwin Hubble where he found that relative velocity of a body in space is directly proportional to the distance of that body from Earth.