The boundary between the Australia Plate and the Sunda Plate is a thick black line.
澳大利亚版块与巽他板块的板块边界在图上以一条粗而黑的线条表示。
2
According to classical theory, at the boundary of a black hole-the so-called event horizon-light can no longer escape.
在经典理论中，在黑洞的边界，即通常所称的事件穹界，光是不能逃逸的。
3
Like carbon dioxide, black carbon absorbs sunlight and infrared radiation, trapping heat in the atmosphere — including the boundary layer closest to Earth's surface.