The adverb: it tells you HOW someone did something — without asking any questions, without checking, without doubting. It attaches to verbs of following and believing: obey unquestioningly, follow unquestioningly, accept unquestioningly, believe unquestioningly, trust someone unquestioningly. The usual position is right after the verb ('she obeyed unquestioningly') or after the object ('they followed him unquestioningly'), though it can also come before the verb in more formal writing ('he unquestioningly accepted every word'). Like the adjective it comes from, it usually carries a small note of worry. If a writer says a group followed their leader unquestioningly, you can normally expect the next sentence to explain why that was a problem. It is not a hard rule — you can use it warmly about a child or an old friend — but the pull is towards criticism, and readers feel it. It is a long word and a formal one. In everyday speech people usually say 'without asking any questions' or 'he just did whatever she said'. Save the long form for writing, or for when you want the sentence to land with some weight.

毫不懷疑地、不假思索地（照做、相信）