along with them goes social mobility,ambition to rise in the urban world,a main factor in bringing down the births in europe in the nineteenth century.

參考答案:

要點：這是一個完全倒裝句，主語是social mobility,ambition to rise in the urban world,a main factor in bringing down the births in europe in the nineteenth century，謂語動詞是goes。ambition to rise in the urban world是對social mobility的進一步說明。a main factor在意思上相當于which is a main factor in bringing down the births in europe in the nineteenth century，修飾ambition to rise in the urban world。

譯文：伴隨他們而來的是社會的流動性，人們強烈地希望在城市里發(fā)展，這是19世紀使歐洲出生率下降的主要因素。