单项选择题
If the sum of five consecutive even integers is 70，what is the value of the greatest of the five integers．（）
A. 12 B. 14 C. 18 D. 20 E. 22
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（）
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（）
