If all the coronary arteries are free of significant obstructions, all parts of the heart will receive equal amounts of oxygen.如果所有的冠状动脉均没有较大的阻塞物，心脏各部分将得到等量的氧气。They're going to operate on an obstruction in her colon.他们准备对她结肠里的阻塞物进行手术。There is a block in the pipe and the water can't flow away.管子里有阻塞物，水流不出去。There must be an obstruction in the drainpipe.排水管里一定有阻塞物。