问题
选择题
Life is not measured by the number of breaths we take, but by the moments _______ take our breath away.
A．that
B．when
C．what
D．who
答案
答案：A
题目分析：本题定语从句的先行词是the moments，后面的定语从句缺少主语，故使用that指代先行词在句中做主语。When在句中不能做主语，who的先行词必须是人；what不能引导定语从句。故A正确，