The first thing a typical traveller possibly does after arriving at a city is search for information online about its popular tourist attractions.
一般旅行者抵达一座城市后,可能做的第一件事就是上网查找有关当地热门旅游景点的信息。
该分句紧跟先行词"thing"并限定其所指。关系代词被省略,可补为"that";补出的关系代词在"does"后充当宾语,因此从句内部存在宾语缺口,属于限制性定语从句。