I had just finished all my homework and

— Peter didn't come to the meeting this morning.

—I _____ him yesterday, but I was too busy and forgot it. [ ]

A. should tell

B. should have told

C. had to tell

D. had told

下列除哪项外，均为细菌人工培养的实际应用

A．病原学诊断
B．细菌的鉴定
C．进行药物敏感试验
D．生物制品的制备
E．传染病的治疗

在窗体上画一个命令按钮和一个文本框，然后编写命令按钮的Click事件过程。程序运行后，在文本框中输入一串英文字母(不区分大小写)，单击命令按钮，程序可找出未在文本框中输入的其他所有英文字母，并以大写方式降序显示到Text1中。例如，若在Text1中输入的是abDfdb，则单击Command1按钮后Text1中显示的字符串是ZYXWVUTSRQPONMLKJIHGEC。请填空。
Private Sub Command1_Click()
Dim str As String,s As String,c As String
str=UCase(Text1)
s=" "
c="Z"
While c＞="A"
If Instr(str，c)=0 Then
s= (6)
End If
c=Chr $ (Asc(c) (7) )
Wend
If s＜＞""Then
Text1=s
End If
End Sub

苯是一种气态污染物。（）

肝硬化患者出血倾向的主要原因是

A．维生素K缺乏

B．血小板数量减少

C．凝血因子合成障碍

D．毛细血管脆性增加

E．肝解毒功能不良而致毒性反应