搜题请搜索小程序“爱下问搜题”
问题 单项选择题

利用激光器使工作物质受激而产生一种单色性高、方向性强及亮度高的光束通过聚焦后集中成一小斑点，聚焦后光束功率( )极高。

A．能量

B．密度

C．值

D．效率

答案

参考答案：B

选择题

It is no use fishing for golden fish in this river; there are _____ left.

A．some

B．a few

C．none

D．many
查看答案
单项选择题

Originally introduced by Netscape Communications, （1） are a general mechanism which HTTP Server side applications, such as CGI （2） , can use to both store and retrieve information on the HTTP （3） side of the connection. Basically, Cookies can be used to compensate for the （4） nature of HTTP. The addition of a simple, persistent, client-side state significantly extends the capabilities of WWW-based （5） .

（2）处填（）。

A．graphics

B．processes

C．scripts

D．texts
查看答案