1.The expressway mars the beauty of the countryside.

1.这条高速公路破坏的田园美景。

2.Bad diction marred the effectiveness of his speech.

2.措词不当影响他演说的效果。

3.A tragedy marred the 1960 cycling competition when Danish cyclist Knur Jensen collapsed and died during the road race.

3.麦自行车选手克那德·金森在公路赛途中倒，当即死亡，这给1960年的自行车赛事蒙上悲剧色彩。