在Rt△ABC中，∠C=90°，
∵AB为斜边，
∴BC=AC?tanA=4×23=83．
As far as I am concerned, education is about learning and the more you learn, _____.[ ]
A. the more for life are you equipped
B. the more equipped for life you are
C. the more for life you are equipped for
D. you are equipped the more for life
脊髓灰质的侧角是（）
A.感觉神经中枢
B.运动神经中枢
C.交感中枢
D.副交感中枢
E.以上全错
