Thank you first! I cannot type Chinese because I am in school now. For the question" 7^548/10,余数是多少." I agree on the answer that the remainder is 1. However, I think the recycle is 07, 49,43,01 because 7^1=7 7^2=49, 7^3=343, 7^4=2401, 7^5=16807. You know it will be different if the question asks 550 instead of 548, the answer will be 49 rather than 9. Is it right?