It has been necessary to refer repeatedly to the effects of the two world wars in promotin

g all kind of innovation. It should be (1)_____ also that technological innovations have (2)_____ the character of war itself by the (3)_____ of new mechanical and chemical device. One weapon developed during World War II (4)_____ a special mention. The (5)_____ of rocket propulsions was well known earlier, and its possibilities as a (6)_____ of achieving speeds sufficient to escape from the Earth's gravitational pull had been (7)_____ by the Russian and the American scientists. The latter built experimental liquid-fuelled rockets in 1926. (8)_____, a group of German and Romanian pioneers was working (9)_____ the same lines and in the 1930s, it was this team that developed a rocket (10)_____ of delivering a warhead hundreds of miles away. Reaching a height of over 100 miles, the V-2 rocket (11)_____ the beginning of the Space Age, and members of its design team were (12)_____ in both the Soviet and United States space programs after the war.

Technology had a tremendous social (13)_____ in the period 1900 1945. The automobile and electric power, (14)_____, radically changed both the scale and the quality of 20th-century life, (15)_____ a process of rapid urbanization and a virtual revolution (16)_____ living through mass production of household goods and (17)_____

The rapid development of the airplane, the cinema, and radio made the world seem suddenly smaller and more (18)_____. The development of many products of the chemical industry further transformed the life of most people. In the years (19)_____ 1945 the constructive and creative opportunities of modern technology could be (20)_____, although the process has not been without its problems.

A．notified

B．observed

C．commented

D．detected