究竟
 Used in questions, the adverb “ 究竟” gives emphasis to the interrogative tone.
究竟+ V\ A
  这位姑娘究竟怎么了，她总是很生气的样子。
  你究竟参加不参加他们的婚礼？
  月亮上究竟有没有植物？ 
究竟+S-PP 
  究竟谁去？
  究竟哪家饭馆最好？
“究竟+S-PP” is often used to form questions about the subject.