针灸治疗脱肛的肾气不固可在基本处方基础上再加（）。 A.阴陵泉 B.气海 C.足三里

请论述对于不同材料的路基和路面结构层应该采取何种方法检测其压实度？

设备购置费的计算公式为( )。

A．设备原价
B．设备原价+工器具购置费
C．设备原价×(1+设备运杂费率)
D．设备原价+设备运输费用

正常人心率超过180次/分时，心输出量减少的原因主要是（）

A.快速射血期缩短

B.减慢射血期缩短

C.心室充盈期缩短

D.心室肌氧气供应不足

E.经减压反射调节后心肌收缩能力减弱

药物的灭活和消除速度决定其（）

A.起效的快慢

B.作用持续时间

C.最大效应

D.后遗效应的大小

E.不良反应的大小

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.

(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.