如果我按10次btn1,会产生多少个线程?  
Read: TThread;是全局变量
procedure TForm1.btn1Click(Sender: TObject);
begin
  if Read<>nil Then
    Read.Resume
  else
    Read:=TThread.Create(false);
end;如果我按10次btn1,会产生多少个线程?  
procedure TForm1.btn1Click(Sender: TObject);
var
  Read: TThread;
begin
  if Read<>nil Then
    Read.Resume
  else
    Read:=TThread.Create(false);
end;
分别产生多少个线程