People were perhaps more honest a long time ago when life was very different from _________ it is to
People were perhaps more honest a long time ago when life was very different from _________ it is today．
A.which
B.that
C.what
D.how
答案及解析： C
解析：
这是一个主语性从句，from后面要跟宾语，且之后的句子缺少成分，只能用what。