、。
She can ask questions and give answers.
Literal
She [topic-は] questions [object-を] do-[connective stem-し], answer [nominalizer-こと] [subject-が] can-do.
質問をし (asking questions, using the masu-stem し as a formal connective) chains with 答えることができる (can answer). The masu-stem used as a conjunctive (し) is more formal than the て-form, giving the sentence a slightly written or academic register. ことができる wraps up both abilities.