Background: The expression of sexually selected traits often varies with populations breeding cycles in many animals. The elucidation of mechanisms underlying the expression of such traits is a resear
中华大蟾蜍(Bufo gargarizans)是广泛分布于我国的一种常见两栖类,目前关于中华大蟾蜍的报道多见于其药用价值和繁殖习性,对其越冬习性及冬眠栖息地生境选择的研究较少。我们采用样线法和样方法对湖南八大公山国家级自然保护区的中华大蟾蜍冬眠栖息地生境特征进行了调查。共测量并记录252个生境样方的植被类型、距人类干扰距离、土地利用类型、地表状况、坡向、坡位、坡度等20个生态因子。
Context:Liver cancer is common in developing countries and it is the most common cancer type in some countries.
教师进行教学活动时,必须要更新教学理念,引领学生参与到学习过程中去,从而让学生形成对问题的深入思考,形成自己个性化的认知,让学生的思维能力形成"看得见"的生长。本文提出要依托新旧链接,在迁移设置中激发疑问;尊重个性认知,在深入探究中解决疑问;强化本源思考,在积极反思中升级疑问;修缮思维路径,在拓展延伸中重生疑问,从而让数学学习真正发生。
The edible straw mushroom Volvariella volvacea is cultivated on a large scale for its unique flavor and nutritious value.