133. If x, y, and z are three-digit positive integers and if x=y+z, is the hundreds digit of x equal to the sum of the hundreds digits of y and z ?
(1) The tens digit of x is equal to the sum of the tens digits of y and z.
(2) The units digit of x is equal to the sum of the units digits of y and z.
答案是A。我的疑问是,如果y和z百位之和大于10,那严格意义上来说,x的百位也不是前两者之和。。。
拜托拜托~