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。
At a special swimming pool in Los Angeles, children become expert at holding their breath under water even before they can walk.
在洛杉矶的一个特设的游泳池里,孩子们甚至在还没有学会走路时就已经能熟练地在水下屏住呼吸了。