space-time 时空

Gravitation is presumably a modification of space - time.  

万有引力则大概是空时的一种变态.

It assumes the strong equivalence priciple, which states that the laws of gravity should act the same, regardless of where in space-time they are tested.

in space-time 修饰where，属于大地点修饰小地点

in space-time是大地点

where是小地点

Where does you live in America?

你住在美国什么地方。