题目内容
(请给出正确答案)
[单选题]
将八种生物按某一依据分成两类,结果如下表,该分类依据是()类群一 乌贼 螃蟹 蚯蚓 蝗虫 类群二 青蛙 蛇 海鸥 斑马
A.是否胎生
B.体温是否恒定
C.有无脊柱
D.生殖方式的不同
答案
C、有无脊柱
如果结果不匹配,请 联系老师 获取答案
A.是否胎生
B.体温是否恒定
C.有无脊柱
D.生殖方式的不同
C、有无脊柱
根据气力输送的特点,降低动力消耗,节约能源是一个重要的研究课题,从经验中知,管道内径是关于能耗的重要参数。直观上看,当输送量一定时,管径过小,输送易阻滞,管径过大,虽输送畅通,但又造成能量的浪费。根据经验,把管径分成三组,各组的试验结果如下表所示,试用方差分析法比较各组的效果.
管径(mm) | 单位功耗 |
230 | 0.0308,0.0476,0.0504 |
250~260 | 0.0532,0.032,0.0218,0.028,0.028, 0.042,0.0336,0.042,0.042,0.028 |
280~320 | 0.07,0.07,0.0644,0.0312,0.0756,0.0756, 0.07,0.0588,0.0588,0.042,0.0308,0.0364, 0.0448,0.21,0.154,0.1064,0.1288,0.112, 0.1064,0.1288,0.0756,0.0644,0.0504,0.0644, 0.0504,0.0308 |
A.分层后每个子总体由一组具有相同特征(通常为货币金额)的抽样单元组成
B.在实施细节测试时,注册会计师通常根据金额对总体进行分层
C.对某一层中的样本项目实施审计程序的结果,可以推断整体项目的结果
D.如果注册会计师将某类交易或账户余额分成不同的层,需要对每层分别推断错报 对某一层中的样本项目实施审计程序的结果,只能用于推断构成该层的项目,选项