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问题 单项选择题

悬臂浇筑法施工适用于预应力混凝土悬臂梁、连续梁、刚构、斜拉桥等结构，通常每次可浇筑（）长的梁段，每个工序循环约需6～10d。

A.1～2m

B.2～3m

C.2～4m

D.3～5m

答案

参考答案：D

填空题

氢氧化钙在日常生活和工农生产中应用非常广泛．如鲜鸡蛋在进行呼吸作用时通过蛋壳表面的大量微小孔隙呼出二氧化碳，为停止鸡蛋的呼吸作用达到保解目的，人们常用石灰水作为鲜鸡蛋的保鲜剂，其原理可用化学方程式表示为______．在农业上，还常用熟石灰与______配制波尔多液．
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单项选择题

Heart AttackIn the United States, and especially in big cities and rural areas, tens of thousands of people with hearts that should be good 【51】 to keep them alive die each year for lack of adequate first aid. In New York City, for example, a new study has shown that only one person in 100 outside of hospitals 【52】 after the heart suddenly stops pumping. In contrast, in Seattle, the survival 【53】 after such heart attacks is one in five."The difference can be traced 【54】 the effectiveness of the chain of survival", Dr. Joseph P. Ornato said. " Each link in the 【55】 must be p enough for many lives to be 【56】 ".The chain begins with an immediate telephone 【57】 for emergency help and the start within four minutes of the process needed for restarting the 【58】 working, by a family member or bystander (旁观者).It continues with the prompt arrival-------within eight 【59】 ten minutes of a rescuer equipped with a special instrument that can shock the heart back to a normal rhythm. And it ends with the administration (给予, 实施) of advanced (先进) emergency care by nurses to maintain the heart’’s ability to survive until the doctors at the hospitals can take 【60】 When one or more links in this chain fail or function too slowly, the 【61】 of a victim surviving heart attack falls rapidly. Because of widespread weaknesses in the chain of 【62】 , experts in emergency heart care estimate that 20,000 to 80,000 people 【63】 needlessly of heart attack each year, a number comparable to the 55,000 killed annually in automobile 【64】 .One expert says, "Sending an emergency vehicle to a heart attack victim, 【65】 the special equipment is like having policemen with guns but no bullets. They may put on a good show, but they lack the weapon needed to get the job done."

A．much

B．enough

C．many

D．too
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