In an operating refrigeration system low on refrigerant, a liquid line sight glass will（）

A . noise coming from that air starting valve B . continuous operation of the starting air compressor C . zero air pressure in the air starting system D . overheated starting air pipe to the cylinder head

A . hour B . day C . week D . month

A . Spark plug B . Heat of compression C . Carburetor D . Glow ping

A . change management B . configuration management C . incident management D . acceptance test pla

A . Tilde （~） B . Hash （#） C . Equals （=） D . Asterisk （*）

A . the four-way control valve failing to shift B . the bleeder valve sticking in the open position C . cold hydraulic fluid D . a clogged air vent falter on the oil reservoir

A . Run c -l 0?from the command line.Run ?c -l 0?from the command line. B . Invoke SMIT for the shell environment. C . Run the SC + H?combination at the command prompt.Run the ?SC + H?combination at the command prompt. D . Use a rep?command with its UID against the /var/log/history_cmds file.Use a ?rep?command with its UID against the /var/log/history_cmds file.

A . excessively late fuel injection B . oil in the air charge C . water in the fuel D . injection continuing after the fuel charge is ignited

A . Undo tablespace B . USERS tablespace C . SYSAUX tablespace D . SYSTEM tablespace E . Temporary tablespace

A . number B . abbreviation C . letter D . All of the above

A . Open-faced diamond B . Diamond with a cross C . Circle D . Rectangle

A . electrical overload B . surging at governed RPM C . loose engine mounting bolts D . coolant leaking into the cylinder

A . Crankshaft revolution B . Type of engine (diesel or gasoline) C . Distance a piston travels during a stroke D . Number of pisto

A . Clean all electrical connections B . Lift the relief valves by hand C . Inspect and clean all solenoid valves D . Inspect for oil and water leak

A、an immediate crankcase explosion B、oil contamination in the compressed air C、a decrease in compressor capacity D、no immediate loss of the compressed air capacity

A . increasing cooling water flow B . increasing lube oil flow C . dilution by fuel oil D . adding SAE 70 oil

A . Method B . Polymorphism C . Inheritance D . Encapsulation

A . feel the high pressure fuel line B . check the cylinder exhausts for white smoke frequently C . check the cylinder exhaust temperature D . isolate each cylinder and inspect the injector

A . Loading B . Discharging C . Crude oil washing D . Steaming tank

A . to open B . opening C . open D . opened

Researchers at the Biorobotics (生物机械技术)Laboratory of McGill University in Montreal are building a robot , known as Micro Surgery robot-1(MSR- I for short), that will perform. delicate operations under the control of a human surgeon. The robot is specifically designed for performing eye surgery but could have other applications, such as the removal of brain tumors. The system could also be used to allow surgeons and their students to practise simulated surgery that feel like the real thing- without the real consequences for the patients. During the operations, the surgeon manipulates a set of control known as the master. These are connected through a high- performance computer to the robot. Both the master and the robot have two limbs, When the surgeon moves the masters' limbs, the robots limbs move in exactly the same way, except that the movements can be scaled down as much as a thousand times. This will eliminate hand tremor and poor accuracy and thus reduce the damage to the eye that can occur with present microsurgery techniques. Each of the robots limbs has a minimum movement of one micrometer---more than one hundred times the precision of the human hand. The computer also creates a three - dimensional robot' s eye view of the inside of the eye that the surgeon can see by wearing a virtual reality helmet (虚拟现实头盔) that has a small lens in front of each eye. To provide the surgeon with such a realistic experience, MSR-I must be able to move rapidly, but this requires extremely fast computing. To handle the computational demands of instant interaction, the McGill team is constructing its own parallel-processing computer., It is al so studying areas such as muscle mechanism, artificial intelligence and optics, and has a already built another micro robot MR- I, capable of manipulating a single living cell. Although commercial applications of the new system are not expected for several years, its basic mechanical components will be ready for testing in a few months, "The day when micro robots will be able to perform. surgery without human intervention is many years away," says Hunter, "in the meantime , a system such as MRS-I is a necessary precursor." The so-called "virtual reality "mentioned in this passage is actually. A．a surgical tool used for operations B．a computer system used to produce life- like illusions C．a new kind of applications in a visual technology. D a way to carry out operations in a visual sense