The correct spelling is noticeable.
A Noticeable is spelled correctly.
noticeable
noticeable
Yes it is spelled correctly
All the given words are the correct spelling in both British English and American English.
You have spelled 'still' correctly.
Yes, engineer is spelled correctly in your question.
Flattest is spelled correctly. The others are spelled: silliest, biggest and sweetest.
Yes, surprisingly is spelled with an S. Surprisingly is how you spell it. You spelled it correctly.
You've spelled it correctly.
Convenience (easy access or availability) is correctly spelled.
yes, that is correct.