A The dry climate of Egypt has helped to preserve the pyramids, and their very shape have made them less likely to fall into ruin.
B It is practically certain that plans were made for the building of the pyramids because the plans of other large works have fortunately been preserved.
C The first thing they had to do was to choose a suitable place.
D Consequently, we are only able to guess at the methods used.
E Many people were killed while building the pyramids.
F They have stood for nearly 5,000 years, and it seems likely that they will continue to stand for thousands of years yet.
答案：46. F 47. A 48. B 49. D 50. C
