单项选择题
If r and 8 are positive integers，each greater than 1，and if 11(s-1)=13(r-1)，what is the least possible value of r+s（）
A. 2 B. 11 C. 2 D. 24 E. 26
单项选择题 What is the least prime number greater than 83？（）
单项选择题 If p and r are prime numbers，which of the following must also be prime（）
