问题补充:
In my opinion, life in the twenty-first century is much easier than .
A. that used to be
B. it is used to
C. it was used to
D. it used to be
答案:
A. that used to be
B. it is used to
C. it was used to
(答案→)D. it used to be
解析:句意:我认为,生活在21世纪要比过去容易得多。 than 引导的是一个比较从句,同一个人或物,现在和过去两个不同的时间进行对比时,应该用人称代词,因此要有主语it,而used to be 是“曾经的那个样子”之意。故选D。