●Communication networks can be classified in terms of their physical arrangement or (73) Three common (73) are the star,bus,and ring.
(73) A.structures
B.topologies
C.protocols
D.frames
第1题:
Display units, printers are(73)device.
A.input
B.output
C.storage
D.communication
第2题:
(73)
A.connection
B.transmission
C.compromise
D.communication
第3题:
第4题:
A basic premise of OGSA is that everything is(71)by a service: a network enabled entity that(72)some capability through the exchange of messages. Computational resources, storage resources, networks, programs, databases, and so forth are all(73). This adoption of a uniform. service-oriented model means that all components of the environment are virtual. More specifically, OGSA represents everything as a Grid service: a Web service that conforms(74)a set of conventions and supports standard interfaces for such purposes as lifetime management. This core set of consistent interfaces, from which all Grid services are implemented,(75)the construction of hierarchical, higher-order services that can be treated in a uniform. way across layers of abstraction.
A.defined
B.represented
C.used
D.passed
第5题:
---- Look! The man at the gate ________ be our headmaster. He is always standing there every morning.
--- - No, it ________ be him. He is holding a meeting in the office now.
A.must, can’t B.must, mustn’t C.can’t, can’t D.can’t, mustn’t
第6题: