print(frame['height'].resample('M', kind='period').mean())写成分组的方法中，错误的是： A: print(frame['height'].groupby(frame.index.dt.month).mean()) B: print(frame['height'].groupby(frame.index.month).mean()) C: print(frame['height'].groupby(frame.index.to_period(freq='M')).mean()) D: print(frame.groupby(frame.index.to_period(freq='M'))['height'].mean())

Click the Exhibit（s） button to view the EMPLOYEES table.      The EMPLOYEE table contains thousands of rows. The EMP_CODE column is the primary key column. At the end of every month， you are required to perform search queries based on the BASIC_SAL+COMM column values. Which type of index will you create？（） A:  B-tree Index B:  Bitmap Index C:  Function-based Index D:  Partitioned Index

Write down the corresponding words. the 1st month of the year _________ the 2nd month of the year _________ the 3rd month of the year___________ the 4th month of the year___________ the 5th month of the year___________ the 6th month of the year___________ the 7th month of the year___________ the 8th month of the year___________ the 9th month of the year___________ the 10th month of the year___________ the 11th month of the year___________ the 12th month of the year___________

10.Consult _____ for questions about earthquakes.　　a. the six index b. index six c. sixth index d. index numbering six A: the six index B: index six C: sixth index D: index numbering six

They have produced ______. A: 10 more pianos this month than last month B: 10 pianos more this month than last month C: 10 pianos this month as many as last month D: 10 as many pianos this month as last month

An animation of a small ball falling, we will record the beginning and end of the ball movement as____. A: key frame B: subdivision frame C: transition frame D: intermediate frame

删除“学生表”中名为“Index姓名”的索引，正确的T-SQL语句为（ ）。 A: DROP INDEX 学生表. Index姓名 B: DELETE INDEX 学生表. Index姓名 C: DROP INDEX Index姓名 ON学生表 D: DELETE INDEX Index姓名 ON 学生表

pages/index/index

唯一性索引的关键字是什么？ A: unique index B: primary index C: index D: full index

txtStr=index=txtStr.index() (index)