By Duality is meant the property of having two levels of structures.

A . No literal value is substituted for a shared cursor.  B . Different execution plans are generated for substituted literal values.  C . The substitution of a literal value will produce different execution plans.  D . The substitution of any literal value will produce exactly the same execution plan.

A .  single layer of firewalling B .  multiple layers of firewalling C .  firewall connections in either an active or standby state D .  an architecture in which all traffic between firewalls goes through application-specific server

A . Having the vessel head toward the sea B . Running before a sea C . Being turned broadside to the sea D . Having the vessel filled with water

A . Lowering the boom B . Raising the boom C . Spotting the boom over the deck D . Swinging the boom athwartshi

A . multiple layers of firewalling B . a method of operating firewalls from multiple vendors C . firewall connections in either an active or standby state D . an architecture in which all traffic between firewalls goes through application-specific servers E . an architecture in which all traffic between firewalls goes through application-specific gateway

A . Stopping the boom B . Topping or lowering the boom C . Moving the boom left or right D . All of the above

A . Bringing the anchor to short stay B . Heaving in all the chain C . Locking the windlass to prevent more chain from running out D . Paying out more chai

A . Lowering it into a cradle B . Placing it in a desired position C . Spotting it with wash primer and red lead D . Two-blocking it

A . The bottom block touches the top block B . The line has jumped the sheaves C . There are turns in the fall D . You have two block

A．Calculability B．Cancellability C．Non - detachability D．Non - conventionality

A Songs sung by zebra finches at a concert. B Songs sung by female finches for male finches C Songs sung by male finches to other finches. D Songs sung by male finches for female finches

A．the amount of time that the writer spends writing a report B．the reader's unwillingness to make an effort to understand a report C．the amount of time that the reader spends reading any report D．the writer's difficulty in presenting reports in an easily-understood style

A.Having the vessel head toward the sea B.Running before a sea C.Being turned broadside to the sea D.Having the vessel filled with water

A.he hoped there would be no more wars in the world B.he wished the Second World War had not happened C.he hoped people would build more bonfires D.he wished people would learn many lessons from the war

A．the report was very well phrased B．Devaney made a very complicated report C．the report deceitfully pictured an already unjust case D．he was doubtful of the fairness of government

A．producers of perfumes like to make advertisements with a famed singing star as statesman B．popular singers like Britney Spears and Jennifer Lopez use different perfumes simultaneously C．customers tend to follow celebrities even in purchasing fragrance D．hot scents are filling the fragrance counters in big stores 此题为多项选择题。

A．fairy stories are still being made up B．there is confusion about different kinds of truth C．people try to modernise old fairy stories D．there is more concern for children's fears nowadays

A．made the best out of the age he lived in B．was conscious of his age C．pursued his interests D．controlled his age