Not enough information to answer sorry!
The change from 632 feet to 312 feet because there is a decrease. When there is a decrease it is modeled by a negative number. All the others show positive increase.
Answer:
He is asking if you have been to the UK before.
I'm not sure the answer, because I haven't read the material, but I can tell you how to answer it. What it is asking you to do is look at the things you've read, and see how they compare. Look at the material and ask yourself, What was the same about their experiences? What was different? Why? Hope this helped.