20．Tom took the police to the spot ____ the accident happened．

A．which　　　　　 B．that　　　　　 　 C．where　　　　 D．when

19．You think you’re poor, but look at people in really poor countries-it’s all ____．

A．relative　　　 　　 B．simple　　　　　　　　 C．similar　　 　　　　　 D．related