关于入侵检测和防火墙的说法中，正确的是（18)。A．防火墙主要是防止内部网络的攻击B．防火墙安装在网

Over the past twenty years, personal computers have brought tremendous changes to the home and the workplace, and many of the most important developments in computer technology are based on lasers.

home and the workplace, and many of the most important developments in computer technology are based on lasers.

5%, far___ income growth.

A、in a bind of

B、 in a manner of

C、 in excess of

D、 in a position to

According to the passage, during the past twenty years, the kakapo ______.

A．was almost extinct

B．was totally less than 24

C．had reached 24

D．bred powerlessly

During the past twenty years, there have been _____ changes in the country;

A.permanent

B.powerful

C.imaginary

D.dramatic

Lowering personal production of waste___everyone over the past decade.

A. benefited

B. has benefited

C. benefits

D. benefiting

The number of car-owners has risen over the past five years.

rise

Over the past five years, there ____________________ in the number

of car-owners.

Compared with retirees nowadays, those in the past twenty years ______.

A．were less interested in participating in learning activities

B．had less choices in the places and forms of learning

C．had no opportunity to engage themselves in learning

D．were offered with dull learning activities by institutes

world's first microprocessor, the brains inside a computer a quarter of a century ago. More than 80% of computers now use Intel chips. This success combined with the dominance of the software provided by Microsoft has helped fuel the steep rise in the sale of personal computers seen over the past ten years. Intel profits in the first three months of this year were more than 1.9 billion dollars compared with just under 900 million over the same period in 1996. Intel is putting much of this down to the success of the MMX launched in January and the enhanced version of the Pentium processor and enabling better computer graphics and sound. But at the same time, Intel warned that revenue in the next three months would be flat and competition is becoming more fierce as smaller rivals in the United States launch chips reckoned to be just as efficient but cheaper.

Over the past ten years, the sharp increase in the sale of personal computers was due to

A．better computer graphics and sound.

B．the enhanced version of the Pentium processor.

C．the success of the world's first microprocessor.

D．successful sales of Intel chips and Microsoft software.