论文部分内容阅读
世界上的树主要有阔叶树、针叶树和棕榈树等三大类型.大多数阔叶树都有宽阔而扁平的树叶.许多阔叶树都属于落叶树木,这就是说,它们的叶子在秋天时会掉落.大多数针叶树都属于常绿树木,这就是说,它们的叶子全年都长在树上.棕榈树没有树枝,它们成长时,树干只长高不长粗.
树的种类
【摘 要】
：
世界上的树主要有阔叶树、针叶树和棕榈树等三大类型.大多数阔叶树都有宽阔而扁平的树叶.许多阔叶树都属于落叶树木,这就是说,它们的叶子在秋天时会掉落.大多数针叶树都属于
【出 处】
：
家教世界·创新阅读
【发表日期】
：
2016年11期
其他文献
★小朋友对蜜蜂会充满好奇心，但不要去招惹它们，因为它们会攻击人类。 ★遇到蜂群围击，一定不要乱跑，要抱头蹲下或趴下，用衣服或书包等遮住脸和头等露在外面的部位。 ★如果不小心被蜜蜂蜇了，马上用肥皂水或盐水清洗伤口，让家长将蜜蜂刺拔出。 ★如果出现头疼、恶心、发烧等症状，一定要告诉家长，让他们带你去看医生。
期刊
Efficient activation of peroxymonosulfate by hollow cobalt hydroxide for degradation of ibuprofen an
Hollow microsphere structure cobalt hydroxide (h-Co(OH)2) was synthesized via an optimized solvothermal-hydrothermal process and applied to activate peroxymonos
案件回放： 有一年暑假，一位13岁的小姑娘去参加学校组织的暑期游泳队。一天游泳回来，教练把她送到离家100米远的地方，让她自己走回去。可从那天起，她再没有出现过。两年后，小姑娘的尸骨在野外被发现。尸体已经腐烂。当时在场的警察，都直着身子站在那里看，只有李昌钰蹲在地上看了一会儿，发现小姑娘的尸骨上少了三根骨头，旁边有一些狗毛。 各位训练有素、身经百战的小侦探们，如果你们在现场看到以上场景的话，会
期刊
CuFe2O4@GO nanocomposite as an effective and recoverable catalyst of peroxymonosulfate activation fo
Recently, heterogeneous activation of peroxymonosulfate (PMS) to oxidatively degrade organic pollutants has been a hotspot. In the present work, copper ferrite-
在过去的十年中,以工伤认定和工伤待遇为主体的补偿体系有了较为完善的发展,工伤康复与工伤预防体系也在逐步建立,工伤保险从单纯的工伤补偿逐步走向了预防、康复、补偿“三
A novel Fe/amine modified chitosan composite (Fe/N-CS) was facilely synthesized and showed higher affinity to both Zn(Ⅱ) and cefazolin (CEF) than its precursor
期刊
A low-temperature synthesis-induced defect formation strategy for stable hierarchical porous metal–o
A stable hierarchical porous metal–organic framework PCN-56 with abundant Lewis acid sites (denoted as Defective-PCN-56) was synthesized by the low-temperature
A comparative study of bismuth-based photocatalysts with titanium dioxide for perfluorooctanoic acid
Bismuth-based material has been broadly studied due to their potential applications in various areas, especially used as promising photocatalysts for the remova