卵在母体内孵化后,由母体直接产生幼体的生殖方式,称为() 。...
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佛尔哈德法是采用K<sub>2</sub>CrO<sub>4</...
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秋季是露地栽培西洋芹的主要季节,生产的关键是苗期注意()和肥水管理。...
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说明被子植物叶的一般结构,并阐述叶的结构是怎样和它的功能相适应的...
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以甲苯为原料进行硝代反应时,主要产物为邻硝基甲苯和对硝基甲苯。...
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莫尔法测定Cl<sup>-1</sup>的含量时,要求介质为中性...
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杧果花期要求干燥温暖天气、降水和高的湿度不利于授粉和坐果,引起(...
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枇杷由生长充实的春梢顶芽发生的夏梢是主要的结果母枝,这种枝条(),故有短结果母枝或中心枝之称。...
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