会计凭证是登记会计账簿的依据。 ( )

干扰素的生物学活性包括（）

A.抑制病毒增殖

B.抑制肿瘤细胞生长

C.免疫调节作用

D.使机体产生抗病毒中和抗体

E.直接杀伤靶细胞

世博会上使用的饭盒、胸卡、证件等都用可完全降解的“玉米塑料”制成，制作的第一步是将玉米发酵制得乳酸（C₃H₆O₃）．乳酸由______种元素组成，其中碳元素的质量分数是______．

河北省某公司向北京仲裁委员会申请仲裁其与北京某企业间的买卖合同纠纷，仲裁委员会受理了申请。北京市某企业为逃避责任，遂出示了一份伪造的证人证言，仲裁庭根据这份证人证言，裁决申请人河北某公司赔偿申请人损失50万元。河北省某公司不服该裁决，并且在收到仲裁裁决后发现了这一情况。若您是河北某公司的代理人，您如何通过法律维护被代理人的权益

A．向仲裁委员会所在地的中级人民法院申请撤销裁决

B．待对方当事人申请执行裁决时，向有关人民法院申请不予执行

C．起诉对方当事人

D．向仲裁委员会所在地的基层人民法院申请撤销裁决

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. namesB. cookies C. software D. extensions

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.

升降带平整区和跑道端安全地区的土质密实度不得低于（重型击实法）。（）

A.85%

B.87%

C.90%

D.92%