Subway is a public service,______ main purpose is to meet People's most basic need ,not economic gains这里为什麽填whose 不填which,给个好的判断方法呗

Subway is a public service,______ main purpose is to meet People's most basic need ,not economic gains这里为什麽填whose 不填which,给个好的判断方法呗
Subway is a public service,______ main purpose is to meet People's most basic need ,not economic gains
这里为什麽填whose 不填which,给个好的判断方法呗

Subway is a public service,______ main purpose is to meet People's most basic need ,not economic gains这里为什麽填whose 不填which,给个好的判断方法呗
which 作定语时,一般有选择的意思,而whose则没有,相当于汉语里的“其”、“它的”