sub.1 -C.sub.4 -alkyl group, x is an integer from 9 to 11 andy and z independently of one another are 1 or 2, but cannot both be 1;a process for their preparation and their use for the preparation of macrocyclic &bgr;-methyl ketones which are valuable fragrances.Kurt Bauer...
for+表示一段时间的状语一段时间+ago since+表示过去的某一时间点从句 来看几个例句吧:Hehaslivedherefor16years.他住在这里有十六年了。Hehaslivedheresince16yearsago.他从十六年前起就住在这里了。Hehaslivedheresince1991.他从1991年起就住在这里了。Hehaslivedheresincehewasborn.他从出生起就住在这里。在対...