Brain tumors can be categorized by their primary site location as either supratentorial, or infratentorial tumors – though some tumors can form in either.

脑肿瘤可以根据它们的原发部位分类为脑幕上或脑幕下肿瘤，某些肿瘤可以同时位于脑幕上和脑幕下。

Meanwhile, pre-construction dredging gets  underway at the site location, before another ship lays the foundations for the caissons  to lie on around the perimeter of the island.

与此同时，在另一艘船为沉箱奠定基础之前，施工前的疏浚工作在现场进行。