a national survey of 1,800 americans aged 18 and older questioned(1) participants (2)on how and when they feel angry in order to build '"a broader social portrait of anger in the united states".
1.questioned 係被動式定過去式
2.點解questioned 後仲有participants ?個subject唔係(a national survey of 1,800 americans aged 18 and older)?
3.可唔可以唔加participant?