选择题
2017 AMC 8 Problem 7: Repeated Three-Digit Number
Let Z be a 6-digit positive integer, such as 247247, whose first three digits are the same as its last three digits taken in the same order. Which of the following numbers must also be a factor of Z?
2017 AMC 8 第 7 题：重复的三位数
设Z为6位正整数，例如247247，其前三位与后三位按相同顺序取相同。下列哪个数字也必须是 Z 的因数
A.
11
B.
19
C.
101
D.
111
E.
1111