"one down,ninety-nine to go" ?
what does it mean?
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Any poet wants their poems to be poetic
"So one down, ninety-nine to go."
------
(The speaker has just been praised for her poem)

Question

"one down,ninety-nine to go" ?
what does it mean?
-----
Any poet wants their poems to be poetic
"So one down, ninety-nine to go." 
------
(The speaker  has just been praised for her poem)

Answer

I would need more context to make sense of this.  But the structure  “X down, Y to go” is usually used to mean that you have accomplished X things out of a list of X+Y things.  Example:  you have to take 5 final examinations, and you just finished your second one.  You can say “Two down, three to go.”

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