When we visited Zhou Zhuang again ten years later, we found it changed so much that we could hardly ________ it.
Of all the methods they provided, ________ is of any help for solving the math problem.
Many people like to talk about generation gaps. I don't think there is ________ in my family though.
I will never know what was on his mind at the time, nor will ________.
When Kerry and Sam met again two years later, each was pleased to see ________.
There is a subway in my hometown, but ________ existed two years ago.