铁路粘油槽车卸油加热约20min左右，关闭（），使加热蒸汽全部进入加热管路，以保证罐

设A，D_j（j=1，2，…，n）分别为线性方程组AX=b的n阶系数矩阵和系数矩阵第了列元素换成常数项后对应的行列式，则（）。

A．若|A|＝o，则线性方程组有无穷多解

B．若|A|＝0，且D_j＝0(j＝1，2，…，72)，则线性方程组有无穷多解

C．若|A|＝0，则线性方程组无解

D．若|A|≠0，则线性方程组有唯一解

火元偏盛药物性能则( )

A．腻、重
B．钝、凉
C．轻、糙
D．热、锐
E．轻、锐

Melissa and LoveLetter made use of the trust that exists between friends or colleagues. Imagine receiving an (6) from a friend who asks you to open it. This is what happens with Melissa and several other similar email (7) . Upon running, such worms usually proceed to send themselves out to email addresses from the victim’s address book, previous emails, web pages (8) .

As administrators seek to block dangerous email attachments through the recognition of well-known (9) , 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 (10) access to your network.

9（）

A.names

B.cookies

C.software

D.extensions

乳腺最常见的良性肿瘤是（）

A.脂肪瘤

B.纤维瘤

C.纤维腺瘤

D. * * 状瘤

E.腺瘤

设有如下程序： Private Sub Form_Click( ) Dim a As Integer，s As Integer n=8 S=0 DO S=S+n n=n-1 Loop While n＞0 Print SEnd Sub以上程序的功能是 【10】 。程序进行后，单击窗体，输出结果为 【11】 。