【单选题】

The history of civil engineering is a very important story in the development of civilization.Civil engineers began practicing their (47) four thousand years ago.Every great civilization,Egyptian, Minoan, and Roman, (48) , had their civil engineers. What is left of their work is proof that they were intelligent. These engineers of the ancient world built entire cities. They (49) systems of pipes which supplied fresh water. They built water pipelines for farm lands as well as bridges of great length. The ruins of their structures tell us (50) about the work of early engineers.Consider the pyramids ofEgypt. They are (51) that some of the earliest engineers had great scientific ability. They are also proof that those engineers could make lasting works of art and design.Although they lived thousands of years ago, theEgyptian engineers used very (52) measurements. The base of the largest pyramid -- the great pyramid near Gizeh -- comes to within inches of being a perfect square, the pyramid is (53) place

D、Each corner points toward the exact directions of north, south, east, and west. The inside of the pyramid is filled with complicated passages and tunnels. These lead to different rooms inside the pyrami
D、Many of these passages are of (54) length and height. The engineers ofEgypt did more than design the pyramids. They (55) set up methods of moving and shaping the building materials. These were very heavy. They had to be brought from miles (56) and sometimes lifted several hundred feet.During the work the engineers commanded thousands of workers. The pyramids remain as evidence of the abilities of the ancientEgyptian engineers. WOR
D、BANKA、away I) greatB、many J) touristsC、also K) evidenceD、profession L) factE、perfectly M) muchF) howeverN) stillG) exact O) designedH) for instance