（）is a computer technology that headsets,sometimes in combination with physical spaces or multi-projected environments,to generate realisitic images,sounds and other sensations that simulate a user’s physical presence in a virtual or imaginary environment.

A small light tackle with blocks of steel or wood that is used for miscellaneous small jobs is called a（）.

If there is a strike or lock-out affecting the cargo on or after vessel’s arrival at port of discharge and the same has not been settled within 48 hours，Receivers shall have the option of keeping vessel waiting until such strike or lock-out is at an end against paying half demurrage after expiration of the time prescribed for discharging or ordering the vessel to a substituting port．The “same” refers to（）.

A block that can be opened at the hook or shackle end to receive a bight of the line is a（）.

A Ezonexam Ethernet switch receives a unicast frame. with a destination MAC that is listed in the switch table. What will this switch do with the frame?

Symmetric, or private-key, encryption is based on a secret key that is shared by both communcating parties. The （ ） party uses the secret key as part of the mathematical operation to encrypt （ ） text to cipher text. The receiving party uses the same secret key to decrypt the cipher text to plain text. Asymmetric, or public-key, encryption uses two different keys for each user: one is a （ ） key known only to this one user; the other is a corresponding public key, which is accessible to anyone. The private and public keys are mathematically related by the encryption algorithm. One key ia used for encyption and the other for decryption, depending on the nature of the communication service being implemented. In addition, public key encryption technoligies allow digital （ ） to be placed on messages. A digital signature uses the sender&39;s private key to encrypt some portion of the message. When the message is received, the receiver uses the sender&39;s （ ） key tp decipher the digital signature to verify the sender&39;s identity.

With reference to a vessel’s structural integrity, the most significant characteristic of a cryogenic liquid is its （）.

（）is entitled to enter into，with a shipper，any agreement，stipulation，condition，reservation or exception as to the responsibility and liability of the carrier or the ship for the loss of or damage to，or in connection with，the custody and care and handling of the goods prior to the loading on，and subsequent to the discharge from，the ship on which the goods are carried by sea.

A person ______ e-mail account is full won’t be able to send or receive any e-mails.

（）means a technique using digital codes which enables a radio station to establish contact with, and transfer information to another station or group of stations and complying with the relevant recommendations of the CCIR.

If the scavenge fire is of a more major nature, if there is a risk of the fire extending or if the scavenge trunk is adjacent to the crankcase with risk of a hot spot developing it sometimes becomes necessary to （）the engine.

What is the action that a GMDSS Radio Operator should take when a DSC distress alert is received? （）