Both tombstones in Figure 1 are from the same cemetery and were erected within four years of each other. Why is the younger marble tombstone more weathered than the older granite tombstone

How do refracting telescopes magnify a far away image? a. by directing light beams to meet at a focal point b. by absorbing light beams’ wavelengths c. by forcing light beams to change direction d. by measuring light beams’ velocity