The rural workforce has been flowing in to the cities ever since the open door policy was adopted.
自從改革開放政策實施以來,農付勞動力正不斷流向城市。
Because of this, we kept looking back, wondering if we were leaving a trail of oil and petrol behind us.
因此,我們不時地掉過頭,懷疑車后是否留下了機油和汽油的痕跡。