— When are the Shutes leaving for New York? 　　 

— Pardon?  

— I asked _____.[ ]

A. when are the Shutes leaving for New York 　　

B. when the Shutes are leaving for New York 　　

C. when were the Shutes leaving for New York 　　

D. when the Shutes were leaving for New York

研究者有目的的控制和改变某些条件，引出所要研究的某些现象，以此得到关于这一现象发生所起作用规律的研究方法是（）

A.实验法

B.访谈法

C.个案法

D.观察法