英语练习3On December12,1901,the Italian electrical engineer Gugl

英语练习3
On December12,1901,the Italian electrical engineer Gugliemo Marconi(1874-1937) succeeded in sending radio signals from England to Newfoundland across the Atlantic Ocean.This is usually taken as representing the invention of radio.Such radio signals are transmitted by the use of radio waves,similar in nature to light waves,but a million or so times longer.
Like light waves,radio waves travel in straight lines,and so a radio-wave transmission should not be detectable beyond the horizon.Nevertheless,Marconi’s signals traveled from England to Newfound around the curve of Earth.
A British-American electrical engineer,Arthur Edwin Kennelly,and an English electrical engineer,Oliver Heaviside,independently suggested in 1902 that radio waves would be reflected by ions(电离子) and that there must be a layer of ions high in the atmosphere that reflected radio waves.(This came to be called the “Kennelly-Heaviside layer.”).Bouncing between the Kennelly-Heaviside layer and the ground,radio signals could travel around the curve of Earth’s globe.
The English physicist Edward Victor Appleton,studying the manner in which beams of radio waves interfered with each other,produced convincing evidence,in 1922,that the theoretical suggestions of Kennelly and Heaviside were accurate and that there was indeed an ion-rich layer in the upper atmosphere.By 1924,he was able to show that the Kennelly-Heaviside layer was some 95 kilometers above the surface of Earth.He also produced evidence for the existence of still higher ion-rich regions (“Appleton layers”) and,in 1926,show as 240 kilometers high.
The portion of the atmosphere lying between heights of 50 and 300 kilometers above the surface of Earth is therefore called the “ionosphere.”
41.According to the first two paragraphs,which of the following is NOT true?
A.Marconi traveled from England to Newfoundland.
B.Marconi was born in 1874.
C.Marconi sent radio waves across the Atlantic.
D.Marconi achieved great success when he was under 30.
42.Kennelly and Heaviside________.
A.suggested the existence of a layer of ions in the atmosphere
B.discovered the “Kennelly-Heaviside layer”
C.detected radio waves sent by each other
D.worked together and made great contributions to science

1,A 是错的.利用排除法.
B Marconi 出后于1874年是对的.根据(1874-1937) 可以看出来是对的.
C Marconi 通过大西洋把无线电波送出去也是对的.从第一句话可以看出来.
D 在Marconi 30岁以下,他取得了巨大的成就也是对的.从第一话可以看出来.
2,B