存储、处理国家秘密的计算机信息系统按照涉密程度实行()保护。
A. 分类
B. 统一
C. 分级
人类基因组的组织特点描述不正确的是
A. 功能相关的基因常散在分布于不同的染色体上
B. 基因组含重复序列
C. 基因组中各个基因的大小和内部组织的差异不大
D. 每个结构基因都有单独的调控序列
Are There Truths in Dreams? Imagine waking up after dreaming (dream) about a terrible plane crash. The next day you will make a plane journey that you have______(41)(plan) long before. Will you get on the plane? A survey shows that you may not cancel your trip. But your dream will probably influence your______(42)(thought) during the journey. You may feel______(43)(worry) and find the trip much______(44)(long) than before. So dreams may influence what we are______(45)(real) doing while we are awake. The explanation of dreams is still a(n)______(46)(clear) area. A team of researchers are entering a new field of studies: Do dreams actually influence our______(47)(behave)? Over the past few years, they have______(48)(do) studies in different cultures and found out that dreams contain some______(49)(hide) truths: dreams affect the way people live and work. But researchers also tell people not to be______(50)(easy) influenced by their dreams. ______.
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请帮忙给出每个问题的正确答案和分析,谢谢!
近年来频发的自然灾害让全球深受其害。炎热的酷暑、狂暴的飓风、刺骨的严寒以及滔天的洪水近乎成了“常客”,风调雨顺已被视为“奢侈品”。
世界各地的气象学家对此众说纷纭。有的说是全球变暖所致,有的说是大气环流异常,还有的认为厄尔尼诺是罪魁祸首。
尽管如此,大多数学者都认同这样一个观点:全球气候变化速度正在加剧,极端灾害天气今后无疑将更加频繁,并且其强度和范围都将走强。面对日益脆弱的全球气候,人类需要更认真地思考,如何切实有效地规范自身活动,珍爱我们共同的家园。
未来极端危害天气将对相关的行业,如水利、农业、林业、能源、健康和旅游业等有更大影响。同时,上述因素也为全球经济复苏带来更多变数。