男性，34岁。气短少尿1周。查体：半坐位，全心扩大，心率134次／分，Af，心音低钝

已知a+b=3，ab=-12，求下列各式的值．

（1）a²-ab+b²

（2）（a-b）²．

治安工作社会化是公安机关在社会治安方面当家做主的体现。 ( )

尿激酶型纤溶酶原激活物（）

A.内源性纤溶的激活物 

B.外源性纤溶的激活物 

C.抗血友病球蛋白 

D.蛋白C抗凝系统物质 

E.丝氨酸蛋白酶抑制物

窗体上有两个文本框Text1、Text2以及一个命令按钮Command1，编写下列程序： Dim y As Integer Private Sub Command1_Click() Dim x As Integer x=2 Text1.Text=p2(p1(x),y) Text2.Text=p1(x) End Sub Private Function p1(x As Integer)As Integer x=x+y:y=x+y p1=x+y End Function Private Function p2(x As Integer,y As Integer)As Integer p2=2*x+y End Function 当单击1次和单击2次命令按钮后，文本框Text1和Text2内的值分别为( )。

A．2 42 4

B．2 44 8

C．4 48 8

D．10 1058 58

An American option is more valuable than a European option on the same dividend paying stock with the same terms because the:()

A. European option contract is not adjusted for stock splits and stock dividends and does not conform to the Black-Scholes model and is often mispriced. 

B. American option can be exercised from date of purchase until expiration, but the European option can be exercised only at expiration. 

C. American options are traded on U. S. exchanges, which offer much more volume and liquidity.