皮皮学，免费搜题
登录
搜题
【单选题】
将数据库导入R语言后，可用（）显示数据库结构，用（）查看数据库行列数，用（）查看每个变量的基本统计值。A.
str(data) summary(data) dim(data)
B.
str(data) dim(data) summary(data)
C.
dim(data) summary(data) str(data)
D.
summary(data) dim(data) str(data)
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】单宁 (tannin)属酚类化合物的衍生物,多以颗粒状存在于细胞质、液泡或细胞壁中,具有抗水解、抗腐烂及动物损伤等生理功能,即具有( )的作用。
【单选题】The following are requirements for sending a registered post EXCEPT
A.
the packet should be fastened with adhesive substance.
B.
the packets should be posted in the mailbox.
C.
the packets should be posted with relevant fee.
D.
the packets should be wrapped in a strong cover.
【判断题】红葡萄酒的酸、涩味道来自酒中的丹宁(Tannin),丹宁是一种酸性物质,主要源于葡萄皮和葡萄籽。单宁含量与红葡萄酒的质量成反比,丹宁含量越高酒的酸、涩程度越大,酒的品质就越差。
A.
正确
B.
错误
【单选题】According to the passage, the Democrats should do the following except ______.
A.
They should move to another country.
B.
They should stop accusing each other of the defeat.
C.
They should work harder for a Democratic victory next time.
D.
They should reconcile with their Republican friends and colleagues.
【单选题】According to the passage, which of the following is true?
A.
Marketeers should be responsible for the burdens of the past.
B.
Marketeers should separate themselves from their personal and cultural history.
C.
Marketeers should disagree on racial prejudices.
D.
Marketeers should take care of the wounded in the war.
【单选题】Which of the following should NOT be considered in writing a poster?
A.
moody
B.
legible
C.
readable
D.
concise
【简答题】Should any other clause in this contract be in conflict with the following supplementary conditions, the supplementary conditions should be taken as final and binding . (省略)
【单选题】Which of the following is NOT a suggestion for dealing with violent programs?
A.
They should be banned only for children.
B.
They should be banned for both children and adults.
C.
They should be banned only for adults.
D.
They shouldn't be banned, for it is art.
相关题目：
参考解析：
知识点：
题目纠错 0
发布
