请在下面空格处填写答案。>>> from pandas import Series
>>> sa = Seri...
问答题请在下面空格处填写答案。>>> from pandas import Series
>>> sa = Series(['a', 'b', 'c'], index = [0, 1, 2])
>>> sb = Series(['a', 'b', 'c'])
>>> sc = Series(['a', 'c', 'b'])
>>> sa*3 + sc*2
0 aaaaa
1 ______
2 cccbb