first available的用法和樣例：
例句
- When this occurs the Researcher must first obtain the agreement of the Respondent concerned.
這種情況下，研究人員必須首先獲得有關的被訪者的同意。 - Southern farmers accomplished this first by using slave labor, then by creating sharecropping, a form of indentured servitude.
美國南方農場主通過使用奴隸首先獲得了這種勞動力資源，而後創造了收益分成種植體制，即一種契約奴役。
