分页:
[1] 2 3 4 5 6 7 8 9 10 下一页 后10页
Part II Reading Comprehension (35 minutes)
Directions: There are 4 reading passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre .
Passage 1
Toward the end of the 19th century scientists believed they were close to a complete description of the universe. They imagined that space was filled everywhere by a continuous medium called the ether. Light rays and radio signals were waves in this ether just as sound is pressure waves in air. All that was needed to complete the theory was careful measurements of the elastic properties of the ether; once they had those nailed down, everything else would fall into place.
1. Ether was believed to be .
A. a medium in which light travels
B. a substance that travels at the speed of light
分页:
[1] 2 3 4 5 6 7 8 9 10 下一页 后10页