DoS攻击是目前黑客广泛使用的一种攻击手段，以下哪些攻击属于DOS攻击？（）

如果遭受到DoS攻击，一般是利用了哪个漏洞()。

计算机网络安全的威胁可分为主动攻击和被动攻击，截获属于被动攻击。

Smurf攻击采用UDP报文，Fraggle攻击采用ICMP报文。

DOS攻击的Syn flood攻击是利用（）进行攻击。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

The （） is used for hauling in or letting out the wires or ropes.

Vessels must be（）valid certificate of nationality or certificated of registry or license.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。