问题
选择题
. My first summer vocation in the high school, _______I spent a fortnight on the farm, is really unforgettable.
A．when
B．that
C．which
D．the one
答案
答案：A
句意“我上高中后的第一个暑假，在农场度过的14天很难忘。”非限制性定语从句不缺少成分，先行词summer vocation指时间，故用when。故选A。