What does this phrase mean: "Goodness me"?

[KYTTIE]

Test No. incompl/elem-34 "Responses (7)", question 3

Jill: 'We've collected thousands of pounds this week for charity.'
Frank: '.........'

(a) Goodness you!
(b) Goodness them!
(c) Goodness us!
(d) Goodness me!

Test No. incompl/elem-34 "Responses (7)", answer 3

Jill: 'We've collected thousands of pounds this week for charity.'
Frank: 'Goodness me!'

Correct answer: (d) Goodness me!

Your answer was: incorrect
Jill: 'We've collected thousands of pounds this week for charity.'
Frank: 'Goodness us!'
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Hi,
Please explain why I couldn't use "us" in this sentence. I think it must go with "we've..."
Thank you

[Torsten]

It's a fixed expression - it's always goodness me or my goodness no matter how many people are involved.
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Test Of English for International Communication
TOEIC Preparation & TOEIC Vocabulary

[Santinat]

This expression is used in USA?

[Torsten]

Sure.
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Test Of English for International Communication
TOEIC Preparation & TOEIC Vocabulary