Is this a wrong sentence ?
The sentence : "
How well they succeed holds enormous consequences for the world economy, where China has emerged as one of the few reliable engines of growth."

I don't konw if there is clerical error in it , so I assume it is wrong , and the below is my modified version .

"How well they successfully holds enormous consequences for the world economy, where China has emerged as one of the few reliable engines of growth."

Please explain it to me , thank you.

Question

Is this a wrong sentence ?
The sentence : "
How well they succeed holds enormous consequences for the world economy, where China has emerged as one of the few reliable engines of growth."

I don't konw if there is clerical error in it , so I assume it is wrong ,  and the below is my modified version .

"How well they successfully holds enormous consequences for the world economy, where China has emerged as one of the few reliable engines of growth."

Please explain it to me , thank you.

Answer

The first sentence is actually correct, but it is a little complex. 
The first part of the sentence ("How well they succeed holds enormous consequences for the world economy, ") means the level of their success will have a large impact on the world economy. 
"How well they succeed" is the subject, "holds" is the verb, "enormous consequences" is the object, and "for the world" is a prepositional phrase modifying the object.

The second half of the sentence ("where China has emerged as one of the few reliable engines of growth") is a clause modifying "the World Economy". It is adjunct information describing the relation between China and the world economy to explain why the level of its success will have such a large impact.

Hope this helps :)