It is difficult to set down an exact formula because cork is a natural product.
要确定脱模剂的精确配方是困难的,因为软木是一种天然产物.
词典精选例句
English is rich in synonyms , which are difficult for English learners to master.
英语中有大量的同义词, 是英语学习者学习词汇的难点.
期刊摘选
At the start the work seemed complex, difficult, heartbreakingly slow.
开始时这件工作似乎十分复杂困难, 而且慢得令人伤心.
词典精选例句
It is difficult to make an accurate estimate of the total available power in the world.
要对世界上全部可用的水力作出精确的估计是困难的.
互联网摘选
