单项选择题
A.longer and larger B.longer and nearer C.smaller and farther D.smaller and nearer
A.We have already got an answer to this question B.We will never get an answer to this question C.We got an answer to this question long ago D.We may get an answer to this question in the next few years
A.25 years B.50 years C.hundreds of years D.a few years