And how is it known that Mars had hafnium - 187 ?那么是如何知道火星有鉿 -187 的 呢 ?This activator is acyl amine - the hafnium activator that ether is a foundation.該催化劑為酰胺 - 醚為基礎的鉿催化劑.Chemical form of hafnium is perchlorate or nitrat...
The persons elected will sit till 31 Dec . , 1973.當選者任期至1973年12月31日.The effective date of this contract will begin from Dec . 30 th, 2007.這個合同的有效期將從2007年12月30日開始.On the evening of Dec. 31, we usually celebrate the New Ye...