Which tow statements are most correct regarding opt-in models?（）

A . There shall be at least 3 ventilator ducts open to the atmosphere B . At least one exhaust duct shall extend from the open atmosphere to the lower portion of the bilge C . At least one intake duct shall extend from the open atmosphere to the lower portion of the bilge D . Only vessels using fuel with a flash point above 110°F need ventilate engine and fuel compartment

A . The catenary in a hawser should be sufficient so that the hawser just touches the bottom B . The hawser is of sufficient length for towing when taut between tug and tow C . Increasing speed usually increases the catenary in the hawser D . Shortening the tow hawser generally decreases the maneuverability of the tug

A .  When a table is dropped， the corresponding indexes are automatically dropped. B .  For each DML operation performed， the corresponding indexes are automatically updated. C .  Indexes should be created on columns that are frequently referenced as part of an expression. D .  A non-deferrable PRIMARY KEY or UNIQUE KEY constraint in a table automatically creates a uniqueindex.

A . Has-a relationships should never be encapsulated. B . Has-a relationships should be implemented using inheritance. C . Has-a relationships can be implemented using instance variables. D . Is-a relationships can be implemented using the extends keyword. E . Is-a relationships can be implemented using the implements keyword. F . An array or a collection can be used to implement a one-to-many has-a relationship.

A . No fog signal B . A prolonged blast at intervals never to exceed more than two minutes C . A prolonged blast followed by two short blasts at intervals never to exceed more than two minutes D . A prolonged blast followed by three short blasts at intervals never to exceed more than one minute

A . Listeners use only the TCP/IP protocol. B . Multiple listener processes can run simultaneously on a host. C . Multiple database instances can be registered with a single listener. D . The listener-related errors can be traced only at the administrative level. E . Only one database instance can be registered with a single listener at any time

A . A final method in class X can be abstract if and only if X is abstract. B . A protected method in class X can be overridden by any subclass of X. C . A private static method can be called only within other static methods in class X. D . A non-static public final method in class X can be overridden in any subclass of X. E . A public static method in class X can be called by a subclass of X without explicitly referencing the class X. F . A method with the same signature as a private final method in class X can be implemented in a subclass of X. G . A protected method in class X can be overridden by a subclass of X only if the subclass is in the same package as X.

A . It is possible for more than two threads to deadlock at once. B . The JVM implementation guarantees that multiple threads cannot enter into a deadlocked state. C . Deadlocked threads release once their sleep（） method’s sleep duration has expired. D . Deadlocking can occur only when the wait（）， notify（）， and notifyAll（） methods are used incorrectly. E . It is possible for a single-threaded application to deadlock if synchronized blocks are used incorrectly. F . If a piece of code is capable of deadlocking， you cannot eliminate the possibility ofdeadlocking by insertinginvocations of Thread.yield（）.

A . Abandon the towing vessel B . Radio for emergency assistance C . Slip the towline and allow it to run off the drum D . Secure all watertight openings on the towing vessel

A .  The default constructor initializes method variables. B .  The default constructor has the same access as its class. C .  The default constructor invoked the no-arg constructor of the superclass. D .  If a class lacks a no-arg constructor， the compiler always creates a default constructor.  E .  The compiler creates a default constructor only when there are no other constructors for the class.

A . COMMIT… B . MERGE… C . UPDATE… D . DELETE… E . CREATE… F . DROP&helli

A . There cannot be a radiotelephone located anywhere except in the wheelhouse B . The officer in charge of the wheelhouse is considered to have the radiotelephone watch C . Only distress messages may be transmitted over channel 13 D . Only the Master of the vessel is allowed to speak over the radiotelephone

A .  In Java programming language only allows single inheritance. B .  In Java programming language allows a class to implement only one interface. C .  In Java programming language a class cannot extend a class and implement a interface together. D .  In Java programming language single inheritance makes code more reliable.

A . The checkpoint frequency decreases with the smaller redo log file size. B . It ensures that all committed data is written to the data files during normal shutdown. C . The frequent full checkpoint in a database can cause the overall degradation of the database performance. D . It prompts the Checkpoint （CKPT） process to write data to the data files and redo information to the onlineredo log file

A . At least two lifeboats B . A radiotelephone C . A radio direction finder D . None of the above

A . The power-driven tug must maneuver to avoid collision B . You must maneuver to avoid the tug and tow C . You must maneuver to avoid collision only if the tug is to leeward and the wind is on your port side D . Both vessels are required to maneuver to avoid collisio

A . It is possible for more than two threads to deadlock at once. B . The JVM implementation guarantees that multiple threads cannot enter into a deadlocked state. C . Deadlocked threads release once their sleep() method's sleep duration has expired. D . Deadlocking can occur only when the wait(), notify(), and notifyAll() methods are used incorrectly. E . It is possible for a single-threaded application to deadlock if synchronized blocks are used incorrectly. F . If a piece of code is capable of deadlocking, you cannot eliminate the possibility of deadlocking by inserting invocations of Thread.yield().

A . Cisco Express Forwarding （CEF） must be enabled as a prerequisite to running MPLS on a Cisco router. B . Frame-mode MPLS inserts a 32-bit label between the Layer 3 and Layer 4 headers. C . MPLS is designed for use with frame-based Layer 2 encapsulation protocols such as Frame Relay， but is not supported by ATM because of ATM fixed-length cells. D . OSPF， EIGRP， IS-IS， RIP， and BGP can be used in the control plane. E . The control plane is responsible for forwarding packets. F . The two major components of MPLS include the control plane and the data plane.

A . The towing line between the two vessels should be clear of the water B . The towing line should be taut at all times between the vessels C . There should be a catenary so the line dips into the water D . None of the above

A .  NAT provides 1 to manyaddress mapping. B .  NAT provides 1 to 1 address mapping. C .  NAT is only useful forTCP/UDP and ICMP traffic. D .  NAT can be used for all IP traffic.

A . It is possible to synchronize static methods. B . When a thread has yielded as a result of yield（）， it releases its locks. C . When a thread is sleeping as a result of sleep（）， it releases its locks. D . The Object.wait（） method can be invoked only from a synchronized context. E . The Thread.sleep（） method can be invoked only from a synchronized context. F . When the thread scheduler receives a notify（） request， and notifies a thread， that thread immediately releases its lock.