But then again, given the popularity of birth tourism - babies born overseas to rich Chinese parents - maybe the fourth traveller is in nappies.

不过另一方面，鉴于“生育旅游”(中国有钱人到海外生子)的流行，第四位旅客或许还裹着尿布。

youdao

Carved in grey stone, the great Chinese traveller looked like the kind of chap who would have difficulty running to catch a bus.

BBC: Following the Silk Road to the end of China