执行以下语句,将输出?( )
>>>list1=['b','c',1,2,3,4,5] >>>list1.append('a') >>>list1.append('a') >>>list1
['b','c',1,2,3,4,5]
['b','c',1,2,3,4,5,'a']
['b','c',1,2,3,4,5,'a','a']
无输出