Hi all,

I have two problems this time.
First of all, a question on plural:
Which one is correct:
1. They open their mouth in astonishment.
2. They open their mouths in astonishment.
In one of my grammar books, it explains that, since each of us has only one mouth, then it should be in singular. Thus I have been using this singular form until I noticed that I was the only one to do that !

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Second question:
'inasmuch as'I know that it means 'because of', 'since', and 'while', but I have no idea how to write a sentence with this conjunction. Kindly give me two examples please.
Thank you!
Nemessos