如图所示,四边形ABCD是梯形,AD∥BC,CA是∠BCD的平分线,且AB⊥AC,AB=4,AD=6,则tanB=( )
A:23
B:22
C:114
D:554
人的一生中,生长发育和智力发展的黄金时期是青春期.
This is . ( )
—I was born in a small village with only three _______ people.