This is as true as astronomical facts get, particularly because we have sent artificial satellites into orbit and seen that our planet is indeed roundish. Most of us (except for a lunatic fringe of flat-earthers) also believe this to be the case.
以我们都认为了解的事物为例：地球（大致）呈圆形。这在天文学上属于事实，特别是因为我们已经把人造卫星送入轨道，亲眼目睹了我们的星球呈圆形。绝大多数人（除认为地球是平的狂热份子外）也相信地球呈圆形。