We ran down to the shore in time to see an enormous animal opposite us _____itself out of the water and then _____ down again, which was a whale..

A．thrown; crashing

B．throwing; crashed

C．throwing; crashing

D．thrown; crashed

在调查设计中，选择合适的调查方法主要取决于（）

A.工作方便

B.研究的目的和条件

C.研究者的主观愿意

D.研究对象所能提供的信息

E.可任意选择