[单项选择]Which of the following is true?（）
A. A company should develop an ISM and implement it
B. A company implementing an ISM properly may obtain a DOC
C. Once a company obtains its DOC, each vessel of this company will obtain a SMC
D. DOC is valid for 60 months unless “major non-conformity” is found

[多项选择]Which of the following are true statements regarding the characteristics of OSPF areas? Select all that apply.（）
A. All OSPF networks require the use of multiple areas
B. Multiple OSPF areas must connect to area 0
C. Single area OSPF networks must be configured in area 1
D. Areas can be assigned any number from 0 to 63535
E. Area 0 is called the backbone area
F. Each OSPF area need to be configured with a loopback interface

[多项选择]Which of the following are true regarding bridges and switches?（）
A. Bridges are faster than switches because they have fewer ports.
B. A switch is a multiport bridge.
C. Bridges and switches learn MAC addresses by examining the source MAC address of each frame received.
D. A bridge will forward a broadcast but a switch will not.
E. Bridges and switches increase the size of a collision domain.

[单项选择]Which of the following is true regarding the use of switches and hubs for network connectivity（）。
A. Switches take less time to process frames than hubs take.
B. Switches do not forward broadcasts.
C. Hubs can filter frames.
D. Using hubs can increase the amount of bandwidth available to hosts.
E. Switches increase the number of collision domains in the network.

[单项选择]Which of the following is true about the fuel injection with an ordinary diesel engine?（）
A. The process begins after TDC
B. The process ends before TDC
C. When the piston is near to the TDC the fuel injection ends
D. None of the above is true

[多项选择]Which of the following statements are true regarding bridges and switches (Choose 3.)（）。
A. Switches are primarily software based while bridges are hardware based.
B. Both bridges and switches forward Layer 2 broadcasts.
C. Bridges are frequently faster than switches.
D. Switches have a higher number of ports than most bridges.
E. Bridges define broadcast domains while switches define collision domains.
F. Both bridges and switches make forwarding decisions based on Layer 2 addresses.

[单项选择]Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?（）
A. In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greater
B. Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the ports
C. No gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engine
D. The gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine

[单项选择]Which of the following conditions is true concerning a flammable liquid with a concentration above the upper explosive limit?（）
A. The mixture is too lean to burn
B. The mixture is too rich to burn
C. The vapor is about to explode
D. Conditions are perfect for combustion

[单项选择]Which of the following statements is true concerning carbon dioxide when used as a fire extinguishing agent?（）
A. Carbon dioxide is corrosive when exposed to fire
B. Carbon dioxide should be applied slowly to a large engine room fire
C. Its total cooling effect is far greater than water
D. Its smothering effect is excellent for class B fires

[单项选择]Which of the following statements is TRUE regarding automatic identification systems (AIS)? （）
A. AIS is a short-range VHF-FM system that automatically broadcasts a vessel's position，course，speed and other safety related information to all those with similar equipment in the area
B. AIS is a one-way centrally managed system that requires the local VTS to send commands to instruct each vessel to broadcast position，course，speed and other safety related information to all those with similar equipment in the area
C. AIS is a global tracking system that relies upon INMARSAT C service to communicate vessel position，course，speed and other safety related information to all those with similar equipment in the area
D. AIS is a short-range 3 cm X-band radar system that automatically sends a vessel's position，course，speed and other safety related information to all those with similar equipment within the area