obstacle的近义词有：obstacle, barrier, obstruction, bar, hindrance。下面这些名词均含"障碍(物)"的含义：obstacle：指在达到目的或前进的过程中必须消除或绕过的障碍物，也指起阻碍作用等情况。barrier：常指临时的或者可能跨越的障碍。obstruction：常既指具体的障碍又可指抽象或喻意上的阻碍。bar：既可指阻止进出或通过的栅栏一类的障碍物，也可用于抽象意义障碍。hind...
The basic substance Willis selected for the strata of his experiments was beeswax.威利斯在他做的试验中选择摸拟地层基本物质是石蜡.The titanium ascorbate was the substance of low toxicity to fish, shellfishand anura.抗坏血酸钛对鱼类 、 类及无尾两栖类皆为低毒物质.musi...