更多"It has been necessary to refer to t"的相关试题:
[单项选择]It has been necessary to refer to the effects of the two world wars in promoting all kinds 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 devices. 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 along the same line, and in the 1930s, it was this team (9) 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
A. notified
B. observed
C. commented
D. detected