It’s always difficult to live in a foreign country, ______ when you don’t speak the language. 

Yesterday I was walking downstairs when I missed my foot and had a bad fall, nothing serious, ______.

It was ________ impossible for her to catch the 9 o’clock train. I know she got up at 9:15．

We must behave ____ at a formal table.

Be careful that a good name of a product doesn’t _______ mean good quality of it.