vb.net使用多线程 结果。。内存占用越来越大

Imports System.Net
Imports System.Text
Imports System.IO
Imports System.Net.Configuration
Imports System.Threading
Public Class Form1
Private Sub Timer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer.Tick
Dim MyT As New System.Threading.Thread(AddressOf BduCount)
MyT.Start()
End Sub
Private Sub BduCount(ByVal Qid As String)
Try
Dim request As HttpWebRequest = WebRequest.Create("http://cp.zhidao.baidu.com/v.php?q=111")
request.KeepAlive = False
request.Timeout = 10000
request.ServicePoint.ConnectionLimit = 1000
request.Method = "GET"
request.GetResponse()
Catch ex As Exception
End Try
End Sub
End Class