这里的wash 和 last 都是动词的特殊用法
某些不及物动词后加表褒义的副词时,该动词是主动表被动,这个动词是名词本身性质属性材料决定的.
下面给出一些句型对比（eg是主动形式表被动含义,cf是该动词作被动形式）：
eg.This kind of car sells well.
cf.This kind of car is sold out.
cf.This car was sold to a lady this morning.
eg.The skill dress washes easily.
cf.The skill dress was washed by the nanny.
eg.The door opens automatically.
eg.The shop opens at 9a.m.every day.
cf.The shop is open eight hours a day.
cf.The shop was opened by a stranger last night.
eg.The rumour spread quickly in the compus.
cf.The rumour was spread by the gossip.
eg.The pen writes smoothly.
eg.The bike rides well.