"Fellow traveller" can have a double meaning, too. It can mean literally travelling together (eg on a train) or it can mean people of the same ideology. People aligned with the Communist party during the Cold War might be referred to by other communists as 'fellow travellers'. There's a hint here (in the word 'evenly') that the ambassador does not mean what he/she is saying.

As everyone has explained, American cheese is processed. If you are used to unprocessed cheese, which is what most of the world eats, the taste and texture will seem very strange to you. It has a very smooth texture. In American you can even buy cheese in a can that comes out in a string.

Just a comment, we say 'in this context' but not 'under this context'. What does this sentence mean in this context? Please me tell what this sentence means in this context?

You might here 'I walked here on foot' but it is repetitive, because there isn't another way of walking!

He looked at me in surprise / with surprise ( which preposition? - Either is fine we were going to the cinema but plans were changed / changed so easily ( passive or active? - either sounds fine, if the plans were changed by someone or something else then I'd used 'were changed', if the people going to the cinema changed them, you could use either. Something doesn't sound quite right about 'so easily' in this sentence - what are you meaning here? Died for his irresposibility ( Is this word correct? I think the word you are wanting is irresponsibility. It's an unusual sentence though. I would read it to mean 'his irresponsibility caused his death' (for example, he drove his car after drinking and died) but it's an almost poetic way of writing it, not a normal speech way. I see your other questions have been answered elsewhere.

and the implication is they are sad thoughts, weighing her down (a heavy heart is a worried or sad heart)

Or Please can (or could) we have a photo together?

to answer questions 2 and 3: you probably want to look this up in a good grammar text, but here's my take as a native speaker (not teacher) of English. 2. Just vs simply - 'It's just a phase'; 'it's simply a phase'. When modifying a phrase, to imply that it is not very important, you can use either just or simply. Just is normal in speech and less formal writing. 'Simply' has an old-fashioned ring about it. It is still common in instruction manuals and possibly in politician's speeches 'That's simply incorrect' where most of us would say 'that's just wrong'. Note that when you're using simply as an adverb from the word simple, you can't replace it with just. 'He spoke simply (ie in a simple way) and clearly'. 3. Just vs only: Again, just is less formal. You would write 'there's only one left' but you could say either 'there's just one left' or 'there's only one left'. 'I'm only going to the shops, I won't be long' or 'I'm just going to the shops, I won't be long'. 'Just' has a slightly more colloquial feel but it is not impolite at all. 'Just' can also be used to mean 'I'm about to do', so in speech "I'm just going to the shops" could mean "I'm only going to the shops" (nowhere else) or "I'm about to go to the shops", that is, I'm in the act of leaving to go to the shops now. Context gives the key. Only is not used this way in most dialects of English.