咽鼓管
参考答案:
为连通鼓室和鼻咽的的管道,分骨部和软骨部。使鼓室和外界的大气压相等,幼儿咽鼓管较成人短、平、宽,故咽部感染易沿咽鼓管侵入鼓室。
I think football is _____ older than basketball . [ ]
A. little
B. a little
C. few
D. a few
每次抛掷一枚骰子(6个面上分别标有数字1,2,3,4,5,6),连续抛掷2次,设A=向上的数字之和为6,求P(A).