In my descriptions, I've noticed that some words aren't being process properly - as in Britain¿s instead of Britains's. However in the same description the word He's and Hasn't are ok. Is this a feed encoding issue?
Almost certainly - there are a number of extended character set apostrophe alternatives that can crop up and appear as encoding errors if not consistent with the character set of your site / other feeds (or even the feed itself).
If everything else is working as expected, first try applying a "UTF-8 Encode" filter to the description field for this feed, re-import and that may be all it is, but if that doesn't resolve the issue, let me know an example page URL (I'll remove before publishing your reply) and I'll look at the exact byte sequence that's in place and work out a suitable search value for use with a Search and Replace Hex filter...
I applied the UTF-8 Encode" filter to the description field but it's still the same as per the following link
You might advise on the Search and Replace Hex filter when you get a chance.
In fact, it appears to be using the literal character "¿" in the raw data which probably indicates a slight encoding confusion up-stream in the feed production; so no need for the Hex version, if you just apply a Search and Replace filter to the Description field for this feed using "¿" (without the quotes) in the Search box, and a regular apostrophe in the Replace box and re-import to apply and that should do the trick...