There are many old people _______ are taking a walk in the park.
A:those
B:which
C:who
D:whom
tall he is now! But last year he was and thin.
下列函数中,在其定义域内是增函数的为( )
①***独立领导革命战争的开始②创建人民军队的开始
③建立农村革命根据地的开始④国共合作的开始