下图中每个小正方形的面积都是2平方厘米，则图中阴影部分的面积是多少平方厘米（） A．

比较大小。（在○里填上“>”“<”或“=”）  

10 - 9○13 - 8                      14 - 7○12 - 6                    12 - 3○14 - 5   

19 - 9○18 - 10                    15 - 9 ○16 - 16                  17 - 9 ○15 - 6  

9+8○19 - 8                         11 - 7○7+7                        14 - 8○16 - 8

患者，男，40岁，全身状况良好，无义齿修复史。左下6拔除1年。要求做固定修复。检查：左下6缺失，缺牙区间隙正常。左下7残冠余2/3并近中倾斜，近中舌尖缺失，髓腔暴露，内干尸治疗，大面积银汞充填。余牙良好。拍片示：左下7髓室内白色致密影，残冠，根尖无异常，口内其余情况良好。

本病例除常规固定桥修复外，还可采用以下哪种修复方案（）.

A.直接进行活动修复

B.对左下7进行全冠修复后，再进行活动修复

C.种植修复

D.A和C

E.B和C

抗精神病药物治疗1周后，治疗效应不明显时（）

A.马上停药

B.继续加大剂量

C.合用其他药物

D.继续观察

E.换用其他药物

下列在征税范围内的房产或其他建筑物，属于房产税征税对象的是（）

A.企业职工宿舍

B.水塔

C.工厂围墙

D.房地产公司出租的写字楼

The Theory of Continental Drift has had a long and turbulent history since it was first proposed by Alfred Wegener in 1910. (46) Vigorously challenged yet widely ignored, the theory had languished for half a century, primarily due to its lack of a plausible mechanism to support the proposed drift. With the discovery of sea-floor spreading in the late 1950’s and early 60’s, the idea was reinvigorated. Plate tectonics is now almost universally accepted. Many details of the mechanism are to be worked out.

The surface of the Earth is divided into approximately six large plates, plus a number of smaller ones. The plates are’ bounded by an interconnected network of ridges, transform faults, and trenches. Ridges, also called spreading centers, occur where two plates are moving away from each Other. As the plates separate, hot molten mantle material flows up to fill the void. (47) The increased heat resulting from this flow reduces the density of the plates, causing them to float higher, thus elevating the boundaries by many thousands of feet above the colder surrounding sea floor. (48) Ridges on the ocean floor form the longest continuous ranges of mountains on the planet, but. only in a very few places on the Earth do these mountains rise above the ocean surface.

New sea floor is constantly being created along spreading centers. Obviously somewhere else old sea floor must be going away. This occurs in trenches, also called subduction zones. Trenches occur along the boundary between two plates that are moving towards each other. (49) Where this occurs, one plate is bent downwards at about a 400 angle and plunges under the other plate’s leading edge, eventually to melt back into the liquid mantle below. As the subducting plate is heated back up to mantle temperatures, certain minerals in the plate melt sooner than others. (50) Minerals that melt at lower temperatures and are lighter than the surrounding material tend to rise, melting their way up through the overriding plate to erupt as volcanoes on the ocean floor. As these volcanoes grow, they rise above the ocean surface to form lines of islands along the leading edge of the overriding plate. Numerous islands of Micronesia and Melanesia in the western Pacific were created in this way.

(48) Ridges on the ocean floor form the longest continuous ranges of mountains on the planet, but. only in a very few places on the Earth do these mountains rise above the ocean surface.