常见的基金产品线类型有（）A．水平式 B．垂直式 C．综合式 D．单一式

证据的质量的分级:

A.第一级：按照特定病种的特定疗法收集所有多个质量可靠的随机对照试验后所作的系统评价；

B.第二级；单个的大样本随机对照试验；

C.第三级：有对照但未用随机方法分组的研究(如设计很好的队列研究、病例—对照研究或无对照)；

D.第四级：无对照的系列病例观察；

E.第五级：专家意见。

下列词语中，有错别字的一组是[ ]

A．帷幕　仰慕　临摹　蓦然回首  

B．脉络　奶酪　烙印　恪尽职守  

C．精湛　勘探　斟酌　不堪设想  

D．瞭望　缭草　嘹亮　星火燎原

水泥的安定性是由什么引起的？

阅读理解。

     The need to feed a growing population is putting much pressure on the world's supply of water. With 97%

of the world's water too salty to salty to be drunk or be drunk or used in agriculture, the worldwide supply of

water needs careful management, especially in agriculture. Although the idea of a water shortage (短缺) seems

strange to someone fortunate enough to live in a high rainfall country, many of the world's agricultural industries

experience constant water shortages.

     Although dams can be built to store water for agricultural use in dry areas and dry seasons, the costs of

water redistribution (重新分配) are very high. Not only is there the cost of the engineering itself, but there is

also an environmental cost to be considered. Where valleys (山谷) are flooded to create dams, houses are lost

and wildlife homes destroyed. Besides, water may flow easily through pipes to fields, but it cannot be

transported from one side of the world to the other. Each country must therefore rely on the management of

its own water to supply its farming requirements.

     This is particularly troubling for countries with agricultural industries in areas dependent on irrigation (灌溉).

In Texas, farmers' overuse of irrigation water has resulted in a 25% reduction of the water stores. In the

Central Valley area of southwestern USA, a huge water engineering project provided water for farming in dry

valleys, but much of the water use has been poorly managed.

     Saudi Arabia's attempts to grow wheat in desert areas have seen the pumping of huge quantities of irrigation

(灌溉) water from underground reserves. Because there is no rainfall in these areas,such reserves can only

decrease, and it is believed that fifty years of pumping will see them run dry.

安装中文输入法后，在WindowsXP中使用（）组合键来启动或关闭中文输入法。