最大的五位数与最小的一位数平均数是______.
最大的五位数是99999,最小的一位数是1,那么:
(99999+1)÷2,
=100000÷2,
=50000.
故答案为:50000.
成人心肺复苏时,胸外按压与通气的比例应为()。
A.20:2
B.30:2
C.15:2
D.25:2
E.40:2
Theory is () in the practice of language teaching. It reveals itself in the assumptions underlying practice, in the planning of a course of study, in the routines of the classroom, in the value judgments about language teaching, and in the decisions that the language teacher has to make day by day.