'Historic' and 'historical' are easily confusable.

　　historic和historical容易攪混。

　　We should take more care of our historic buildings.

　　我們應該更加愛護有歷史意義的建筑。

　　The amount of litter in the streets is unbefitting for a historic city.

　　街道上垃圾之多與歷史名城不協(xié)調。