The rural workforce has been flowing in to the cities ever since the open door policy was adopted.
自从改革开放政策实施以来,农付劳动力正不断流向城市。
Forest fires are often caused by broken glass or by cigarette ends which people carelessly throw away.
森林火灾时常由破碎的玻璃或人们随手扔掉的香烟头引起。