(1) ①这些短语均可作“踩倒，踏倒”解。

• The cows have got into the field and trampled the wheat down just as it was ripening!
  这些牛闯进了田地，踩倒了正在成熟中的麦子。
• You could see where the grass had been trodden down by all the people passing across the field.
  你能看到被横穿而过的人们踩得一片狼藉的草地。
• His horse stamped down some of the enemy.
  他的马踩倒了一些敌人。

②trample down也作“残酷对待”解。

• The dictator trampled down his opponents.
  这位独裁者残酷对待他的反对者。

③tread down还有“残暴统治，蹂躏”之意，常用被动式。

• The people have been trodden down for too long, and soon will rise to overthrow their unjust rulers.
  人民被蹂躏得太久了，很快就会起来推翻他们不公正的统治者。

 (2) ①trample (sb./sth.) under foot也是“踩，践踏”的意思。

• Those cattle have trampled the crops under foot again!
  那群牛又践踏了庄稼。
• Many people were trampled under foot in the rush to get to the emergency exit.
  大家争先恐后涌向紧急出口，很多人被踩在脚下。

②trample (sb./sth.) under foot还有“残暴统治，严厉管制”之意。

• The new teacher mistakenly thought that the best way to control the class was to trample them under foot .
  这位新来的老师错误地认为管理这个班级的最好办法是进行严厉管教。