Thomas came down with chickenpox at the weekend.托马斯周末染上了水痘。Then both groups were vaccinated with a chickenpox vaccine.然后两组都接种水痘疫苗.Chickenpox is a highly contagious infectious disease caused by the varicella - zoster viru...
这就是所谓的催化裂化.It is known as catalytic cracking.裂化是使较重的低挥发性的碳氢化合物分裂成较小分子的化学分裂.Cracking involves the chemical breakdown of higher, less volatile hydrocarbons into smaller molecules.FCC(流化催化裂化 ) 是炼厂生产汽油的主要方法之一.The Fluid Catal...
我的祖父是苏格兰矿工工会干事。My grandfather was secretary of the Scottish Miners' Union.数学最差的学生竟被选为班级财务干事,这真是具有讽刺意味.It's ironical that the weakest student in mathematics was elected class treasurer.他干事有他的一套.He has his own se...