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问题 计算题

如图所示，有倾角为30°的光滑斜面上放一质量为2kg的小球，球被竖直挡板挡住，若斜面足够长，g取10m/s2，求：

（1）球对挡板的压力大小；

（2）撤去挡板，2s末小球的速度大小。

答案

（1）

（2）10m/s

选择题

2011年4月，我国居民消费价格指数（CPI）同比上升5.3%。为有效控制通货膨胀，政府应采取的财政政策和措施是[ ]

A、削减行政开支，减少财政支出

B、增加国家税收，扩建公用设施

C、减少国家税收，减持外国国债

D、增加财政支出，刺激需求增长
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单项选择题

Melissa and Love Letter made use of the trust that exists between friends or colleagues. Imagine receiving an (26) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (27) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’s address book, previous emails, web pages (28) .
As administrators seek to block dangerous email attachments through the recognition of well-known (29) , virus writers use other extensions to circumvent such protection. Executable (.exe) files are renamed to .bat and .cmd plus a whole list of other extensions and will still run and successfully infect target users.
Frequently, hackers try to penetrate networks by sending an attachment that looks like a flash movie, which while displaying some cute animation, simultaneously runs commands in the background to steal your passwords and give the (30) access to your network.

A．memory

B．caches

C．ports

D．registers
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