What can be taught, Gao Yang has already taught. Some people can continue to make progress after his instruction, but others seem to reach a plateau no matter how hard they train. This is where natural talent comes into play, and human talent is always limited. Just like how Gao Yang can never hope to become a doctor like Andy He in his lifetime.
Taylor's mid-range shooting is also pretty good. His mission often requires engaging targets at medium to long ranges. Although most of the time, his tasks must be completed in silence, and firing his gun would mean mission failure, he must be capable of using medium and large caliber firearms, and use them well enough. Therefore, Taylor's mid-range shooting is quite skilled. By Gao Yang's standards, Taylor can be rated as good.
