We plant trees______________, and the young trees grow taller______________.
A. year by year; year after year B. year after year; year by year
C. year by year; year by year D. year after year; year after year
We plant trees______________, and the young trees grow taller______________.
A. year by year; year after year B. year after year; year by year
C. year by year; year by year D. year after year; year after year
B