Welcome to the zoo! OpeningFeesMonday to

单项选择。

We              to the park yesterday. [ ]

A. went                        

B. goes                         

C. go

如图2所示，一足够长的木板B放在水平地面上，木块A放在B的水平表面上，A的左端连有轻质弹簧，弹簧左端固定在竖直墙壁上，用力F向右拉动木板B，使B以速度做匀速运动，A相对地面静止时，弹簧的弹力为F₁。已知木块与木板之间、木板和地面之间的动摩擦因数相同，A始终在B上，则以下说法中正确的是（   ）

A．A相对地面静止后，B受到的滑动摩擦力的大小等于F₁

B．A相对地面静止后，地面受到的滑动摩擦力的大小等于F₁

C．若B以的速度产速运动，A相对地面静止后，A受到的滑动摩擦力的大小等于F₁

D．若用2F的力作用在木板B上，A相对地面静止后，A受到的滑动摩擦力的大小等于2F₁

关于烟雾病的正确描述是（）

A.脑实质病变皆为缺血性

B.主要累及颈内动脉系

C.脑底异常血管网来自椎一基底动脉系的侧支循环

D.脑内单发病灶多见

E.常常合并脑静脉异常扩张

Melissa and LoveLetter made use of the trust that exists between friends or colleagues. Imagine receiving an (46) from a friend who asks you to open it. This is what happens with Melissa and several other similar E-mail (47) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’s address book, previous emails, web pages (48) .

A. cracker B. user C. customer D. client

As administrators seek to block dangerous email attachments through the recognition of well-known (49) , 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 (50) access to your network.

设计黑盒测试的测试用例

某图书出租商店欲开发一个租书信息管理系统，管理图书的租借业务。

该系统的数据流图如下：

根据系统的数据流图，画出对应的程序功能图。

（提示；在程序功能图中不考虑文件和与文件交互的数据流，并可用状态和迁移来描述。）