An operational amplifier, as used in todays consoles, has a calculated gain of 5This means that when the input changes （）

A . a cracked liner B . burning lube oil C . an overloaded engine D . insufficient combustion air

A . Coast Guard B . National Cargo Bureau C . Minerals Management Service D . builder

A . high input impedance, high gain and low output impedance B . high input impedance, high gain and high output impedance C . low input impedance, low gain and high output impedance D . low input impedance, high gain and low output impedance

A . Flexibility of operation B . Greater operational safety C . Lower stevedoring costs D . Reduction of cargo damage

A . Thin，metal，air tight cell B . Curved tube containing alcohol C . Column of mercury supported by atmospheric pressure D . Expansion of mercury in a closed tube

A . fiber dispersion B . signal attenuation C . transmitter power D . amplifier bandwidth E . receiver dispersion tolerance

A . increase the field excitation B . decrease the field excitation C . increase the number of magnetic poles D . increase the speed of the prime mover

A . the routing agreement for a particular ocean region B . The communication service he required C . the positions of his ship and the CESs D . B and C

A . lifeline B . painter C . drogue D . marker

A . 1 volt, the output changes 5 volts B . 5 volts, the output changes 1 volt C . 5 volts, the output changes 10 volts D . 10 volts, the output changes 5 volt

A . sliding bowl bottom B . bowl hood C . bowl D . filter unit

A . removing the top half of the shell，cutting the line at its source，and renewing completely B . cutting the line where it enters the case and replacing that portion C . leaving the original line and tying another one to it so the two lines will take the strain D . an approved servicing facility ashore

A . Create a view on the table. B . Create an index on the table. C . Create a synonym on the table. D . Add a virtual column to the table. E . Update the table using the UPDATE statement. F . Delete rows in the table using the DELETE command

A .  Backup-based database duplication. B .  Active database duplication. C .  Tablespace point-in-time recovery. D .  No operation requires the creation of an auxiliary instance.

A . radio signals reflect from a solid surface B . sound waves travel at a constant speed through water C . radar signals travel at a constant speed through water D . pressure increases with depth

A .  fiber dispersion B .  signal attenuation C .  transmitter power D .  amplifier bandwidth E .  receiver dispersion tolerance

A．was first founded by railroad companies. B．has designed an online course for drivers. C．has helped 15,000 drivers to get their licenses. D．collects membership fees from professional truckers.

A．acting B．limiting C．performing D．assuming

A．Interest expense B．Depreciation and amortization C．Selling, general and administrative expenses D．Research and development