下列各术式中，属于无张力疝修补术的是（）。 A.利用人Ⅰ合成材料进行的疝修补术 B.

由乙烯推测丙烯（CH₂=CH-CH₃）与溴水反应时，下列反应产物正确的是 [ ]

A．CH₂Br-CH₂-CH₂Br

B．CH₃-CBr₂-CH₃

C．CH₃-CH₂-CHBr₂

D．CH₃-CHBr-CH₂Br

The oldest stone buildings in the world are the pyramids. They have stood for nearly 5,000 years, and it seems likely that they will continue to stand for thousands of years yet. There are over eighty of them scattered along the banks of the Nile, some of which are different in shape from the true pyramids. The most famous of these are the “Step” pyramid and the “Bent” pyramid.

Some of the pyramids still look as much alike as they must have been when they were built thousands of years ago. Most of the damage suffered by the others has been at the hands of men who were looking for treasure or, more often, for stone to use in modern buildings.The dry climate of Egypt has helped to keep the pyramids in good condition, and their very shape has made them less likely to fall into ruin. These are good reasons why they can still be seen today, but perhaps the most important one is that they were planned to last forever.

The “Step” pyramid had to be on the west side of the Nile, the side on which the sun set. This was for spiritual reasons. It also had to stand well above the level of the river to protect it against the regular floods. It could not be too far from the Nile, however, as the stones to build it needed to be carried in boats down the river to the nearest point. Water transport was , of course, much easier than land transport. The builders also had to find a rock base, which was not likely to crack under the great weight of the pyramid. Finally, it had to be near the capital, or better still, near king’s palace so that he could visit it easily to personally check the progress being made on the final resting place for his body.

63. Which of the following statements is TRUE about the “Step” pyramid?

A. It is unlikely to fall into ruin in the near future.

B. It was built on the sands along the Nile.

C. It is the oldest building on earth.

D. It is the most famous of the true pyramids.

64. The most important reason why some pyramids remain in good condition is that _______.

A. people have taken care of them

B. it doesn’t rain often in Egypt

C. they were well designed

D. the government has protected them from damage

65. Most of the damage to the pyramids has been caused by _______.

A. the regular floods                 B. the dry climate of Egypt

C. people searching for gold           D. people in search of building materials

66. Why did Egyptians build the pyramids along the banks of the Nile?

A. Because they believed in their god.

B. Because it was difficult to find a large rock base far from the Nile.

C. Because the river helped a lot in the transport of building materials.

D. Because it was not easy to choose a suitable place for the pyramids. 

注射成型的三大工艺条件为：温度、压力、（）。

一个供应商可供应多种零件，而一种零件可由多个供应商供应，则实体供应商与零件之间的联系是______。

A．一对一

B．一对多

C．多对一

D．多对多

根据花茎的颜色不同，油菜薹有______。

A．紫色和青色

B．红色和白色

C．绿色和白色

D．紫色和红色