下列关于可变更、可撤销的合同的表述中，不正确的是（）。

A.可变更、可撤销的合同，自当事人知道或者应当知道撤销事由之日起1年内行使撤销权，否则人民法院不予保护

B.可变更、可撤销的合同一经撤销，则视同无效合同，自合同成立之日起无效

C.可撤销合同受除斥期间的限制，一方当事人就撤销合同之诉主张诉讼时效抗辩的，法院不予支持

D.合同被撤销后，返还财产、赔偿损失请求权的诉讼时效期间从合同成立之日起计算

Melissa and Love Letter made use of the trust that exists between friends or colleagues.　Imagine receiving an __(71)___from a friend who asks you to open it.　This is what happens with Melissa and several other similar email __(72)___.Upon　running ,such worms usually proceed to send themselves out to email addresses from the victim's address book, previous emails, web pages__(73)___.

As administrators seek to block dangerous email attachments through the recognition of well-known ___(74)____,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 __(75)__access to your network.

（75）处填（）。

A．cracker

B．user

C．customer

D．client