a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
同义词：iridium??/??Ir??/??atomic number 77
a board of the British government that administers and collects major direct taxes
同义词：Inland Revenue??/??IR
The American Food and Drug Administration says R.F.I.D.tags act like an electronic safety net to make it easier to catch counterfeits.
VOA : special.2010.03.01
P dV is equal to R dT. pV = RT for 1 mole, pdV=RdT so I just take dV here.
对等压过程，那么。
热力学与动力学课程节选 : 麻省理工公开课
He urged revival of the slave-trade in the late 1850s, and he developed a theory of what he called warranteeism--w-a-r-r-a-n-t-e-e-I-s-m.
他促成了十八世纪五十年代后期,奴隶交易的复苏,还自己发明了一套理论,名为抵押品主义
美国内战与重建课程节选 : 耶鲁公开课
A calf is a young cow. A young female cow, especially one that has not yet had a calf, is called a heifer: H-E-I-F-E-R.
VOA : special.2009.07.21
When I was a young child in school, I had to learn the three R's.
VOA : special.2009.07.26
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。