【单选题】By the first century A.D, historians say, the Chinese had some knowledge of the winds and currents of the Pacific. When weather prevented the Chinese from navigating by the sky their mariners(水手) used...
【单选题】Some historians say that the most important contribution of Dwight Eisenhower's Presidency (总统任期)in the 1950s was the U. S. interstate highway system. It was a 【B1】 project, easily surpassing the scal...