The 1992 united nations framework convention on climate change calls for stabilizing the atmospheric co2 concentration at a “ safe ” level , but it does not specify what the maximum value should be 1992年，联合国气候变迁纲要公约呼吁，大气中的二氧化碳浓度应稳定保持在安全范围，却没有指出最大限制应该是多少。
The following attractions offer varying degrees of accessibility for guests using wheelchairs . please see a cast member for further details . guests may remain in their wheelchairs for the entirety of these attractions 为了让行动不便的游客也能在安全范围下尽可能的搭乘园内的游乐设施，下列设施设有不同程度的辅助设备，详情请洽服务人员。
Base on the analysis , the design of the pipe coupling is optimized by bringing forward a dimension scheme of the coupling which increase the connecting force and keep the maximal stress intensity within the safe scope 最后，通过模型，分析了管接头尺寸对管接头系统的强度的影响，并对管接头进行了优化设计，提出了一个能增大抱紧力，并保持最大应力强度在安全范围内的优化方案。
The optimizing theory is introduced to the calculation of the stayed - buckle - cable forces in the process of segment hosting construction of the steel - pipe arch and adjusting construction error . the calculated optimum cable forces with high precision can always guarantee the inner forces and the structure distortion in safe state and ensure the line shape of the arch according with design objective 同时将优化理论引入到钢管混凝土拱桥拱肋架设和调整中的扣索索力计算中，使计算出的索力既能确保结构的受力状态和变形始终处在安全范围内，又能保证架设和调整后的拱肋线形符合设计期望，而且索力的计算精度较高。
Dynamically and statically , the paper analyses the sustainability of national debt policy and financial risk in china : dynamically , financial risks can be within safe scope if basic deficit ratio can be kept between 1 percent and 2 percent ; statically , studing the warning line of financial risks , the author analyses the usages of treasure bonds , favouring that it should mainly support system reformation and economic restructuring in the future . at last the writer makes a research for applying policy on the size and types of treasure bonds in macroeconomic regulation 笔者从动态和静态两个角度对我国国债政策的可持续性和债务风险进行了分析，从动态看未来我国保持1 ? 2的基本赤字率可将债务风险控制在安全范围之内。从静态角度对债务“警戒线”进行了分析，笔者认为我国仍有较大的增发国债的空间。从我国当前的特殊矛盾和防范债务风险两个方面笔者分析了我国国债资金使用方向的改革，认为未来我国国债资金主要应用于支持体制改革和结构调整。
Through field investigation and laboratory analysis of social - economic data , the results were attained as follows : land use structure has a trend to be stable ; the agricultural inputs of labor and capital and the income of agriculture are increasing ; the quality of soil is improved ; the pollution of water and soil are controlled within standard 本研究通过野外调查和实验室分析，结合分析多年的社会经济统计数据，揭示了平谷区农用土地利用变化的特点：土地利用结构趋于稳定；劳动集约和资金集约相结合，土地集约化水平较高；土地生产率和经济效益都在提高；水土资源质量还在安全范围内。
