● The human population has never been bigger, but in some ways the planet seems to be 【小题1】 【小题2】 【小题3】. In the past, travelers from 【小题4】 【小题5】 【小题6】 spent months at sea. Now you just have to sit on a plane for a few hours. When you arrived in another country a hundred years ago, you saw 【小题7】 【小题8】 【小题9】 of clothing and buildings and discovered a 【小题10】 【小题11】 【小题12】 culture.（Fill in each blank with the missing words according to the text.）