（）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.

In a general cargo crane, （） is fitted to raise or lower the jib.

（ ）Is red a strong color or a peaceful color?

The Master or person in charge of a ship is required to log（）.

Project（71）is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

● Project（71）is an uncertain event or condition that, if it occurs, has a positive or a negative effect on at least one project objective, such as time, cost, scope, or quality.（71）

 ______ twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.

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

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

Jitter is an unwanted variation of one or more characteristics of a periodic signal in electronics and telecommunications and（）refers to call issues that cause variations in timing or time of arrival.

What is the purpose of the OSPF router ID in a OR/BOR election?（）

A mark or place at which a vessel comes under obligatory entry，transit，or escort procedure is know as（）.