如图所示，用绳将重球挂在墙上，不考虑球与墙面间的摩擦，若果把绳的长度增加一些，则球对绳的拉力F₁和球对墙面的压力F₂的变化情况是（　　）

A．F₁增大，F₂减小

B．F₁减小，F₂增大

C．F₁减小，F₂减小

D．F₁增大，F₂增大

Sensible peopl don’t think it is_______ to buy things which are not needed even at a low price.

A．worth

B．worthy

C．wothless

D．worthwhile