Q17: PP53

The ability of scientists to provide models of the atmosphere’s complex responses to changing conditions, like seasonal and daily cycles or different planetary conjunctions, have become ever more accurate.

1. The ability of scientists to provide models of the atmosphere’s complex responses to changing conditions, like seasonal and daily cycles or different planetary conjunctions, have become ever more accurate.

2. The ability of scientists has become ever more accurate in providing models of the atmosphere’s complex responses to changing conditions, such as seasonal and daily cycles or different planetary conjunctions.

3. Scientists have become able to provide ever more accurate models of the atmosphere’s complex responses to such changing conditions as seasonal and daily cycles or different planetary conjunctions.

4. Scientists have become ever more accurate in their ability for providing models of the atmosphere’s complex responses to changing conditions, like seasonal and daily cycles or different planetary conjunctions.

5. Scientists’ ability to provide models of the atmosphere’s complex responses to such changing conditions as seasonal and daily cycles or different planetary conjunctions have become ever more accurate.

答案是C没问题，但是我没搞懂，C里的这个to是provide...to还是responses...to？？？