fix some data issues in parallel/parallel multiple answers

[vandyxiaowei]

some parameters have default value, so it should be acceptable if the model doesn't predict the parameter. add "" in the possible answers for those cases.

Please take a look. Thanks!

[HuanzhiMao]

Hi @vandyxiaowei,

Thanks for contributing!

One minor request: Could we exclude the linting changes from this PR? This would help better highlight the changes to the possible answers. Right now the "Files changed" section indicates over 200 additions and deletions, which are predominantly whitespace alterations. These do not impact the evaluation pipeline's correctness but could obscure the actual modifications to possible answers when other people look at this PR.