list1=[1,3,4]
list2=[3,5,2]
(list1+list2)*2的值为？
[8,16,12]
[1,3,4,3,5,2,1,3,4,3,5,2]
[1,3,4,1,3,4,3,5,2,3,5,2]
[2,6,8,6,10,4]
