单项选择题
In a certain country,a person is born every3 seconds and a person dies every 10seconds.Therefore,the birth and death rates account for a population growth rate of one Person every()
A.A B.B C.C D.D E.E
A. $90,000 B. $96,000 C. $108,000 D. $135,000 E. $180,000
A. 25 B. 27 C. 30 D. 45 E. 55