市场调查方法依调查资料来源及资料收集方法可分为（）两类。

A．数据调查和征集调查

B．文案调查和征集调查

C．数据调查和实地调查

D．文案调查和实地调查

All of the following are distress signals EXCEPT（）.

A.the continuous sounding of any fog signal apparatus

B.giving five or more short and rapid blasts of the whistle

C.firing a gun at intervals of about a minute

D.a barrel with burning oil in it，on deck