There exist some unassailable problems in traditional chrome tanning, such as low exhaustion of chrome, salt pollution from pickling, and time-consuming process, etc.
传统浸酸铬鞣存在着一些不容忽视的问题，如：铬的吸收率低，浸酸时带来的盐污染，鞣制周期长等。
And this trend is due, he says, to the exhaustion of the supply of low-hanging economic fruit.
他说，这种趋势是由于发达国家已无遗力再提供唾手可得的经济成果。
The results showed that:(1)The primary teachers' job burnout seemed as a high emotional exhaustion, low depersonality and high efficacy state.
调查发现：（1）小学教师的职业倦怠呈现出高情绪衰竭、低去个性化、高成就感的趋势；
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