Between the two generations, it is often not their age,____their education that causes misunderstanding.

The archaeologists found gold coins and pottery in the lowest level of the site____ they reached three months ago．

When the old man was ___ , he felt ___.

“Who Moved My Cheese?”, ____________ is a best-selling book, is written by Spencer Johnson.

Do you think it is going to rain over the weekend —–__________.