diff --git a/src/Color/Main.cs b/src/Color/Main.cs
index 55a4367..1594f00 100644
--- a/src/Color/Main.cs
+++ b/src/Color/Main.cs
@@ -1,6 +1,6 @@
 namespace Dot.Color;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 
 {
     public Main(Option opt) : base(opt) { }
diff --git a/src/Color/Option.cs b/src/Color/Option.cs
index 8aaf317..f1e3fed 100644
--- a/src/Color/Option.cs
+++ b/src/Color/Option.cs
@@ -1,4 +1,4 @@
 namespace Dot.Color;
 
 [Verb("color", HelpText = nameof(Str.ScreenPixelTool), ResourceType = typeof(Str))]
-public class Option : IOption { }
\ No newline at end of file
+public class Option : OptionBase { }
\ No newline at end of file
diff --git a/src/DirOption.cs b/src/DirOption.cs
index 7504ca9..46acf25 100644
--- a/src/DirOption.cs
+++ b/src/DirOption.cs
@@ -1,6 +1,6 @@
 namespace Dot;
 
-public class DirOption : IOption
+public class DirOption : OptionBase
 {
     [Option('f', "filter", HelpText = nameof(Str.FileSearchPattern), Default = "*.*", ResourceType = typeof(Str))]
     public string Filter { get; set; }
diff --git a/src/Guid/Main.cs b/src/Guid/Main.cs
index 8bf6cb3..9c46163 100644
--- a/src/Guid/Main.cs
+++ b/src/Guid/Main.cs
@@ -2,7 +2,7 @@ using TextCopy;
 
 namespace Dot.Guid;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 {
     public Main(Option opt) : base(opt) { }
 
diff --git a/src/Guid/Option.cs b/src/Guid/Option.cs
index ecc826b..c40c4b2 100644
--- a/src/Guid/Option.cs
+++ b/src/Guid/Option.cs
@@ -1,7 +1,7 @@
 namespace Dot.Guid;
 
 [Verb("guid", HelpText = nameof(Str.GuidTool), ResourceType = typeof(Str))]
-public class Option : IOption
+public class Option : OptionBase
 {
     [Option('u', "upper", HelpText = nameof(Str.UseUppercase), Default = false, ResourceType = typeof(Str))]
     public bool Upper { get; set; } //normal options here
diff --git a/src/IP/Main.cs b/src/IP/Main.cs
index f772d53..5c934ef 100644
--- a/src/IP/Main.cs
+++ b/src/IP/Main.cs
@@ -3,7 +3,7 @@ using System.Net.Sockets;
 
 namespace Dot.IP;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 
 {
     public Main(Option opt) : base(opt) { }
diff --git a/src/IP/Option.cs b/src/IP/Option.cs
index d3ef77a..5ed2605 100644
--- a/src/IP/Option.cs
+++ b/src/IP/Option.cs
@@ -1,4 +1,4 @@
 namespace Dot.IP;
 
 [Verb("ip", HelpText = nameof(Str.Ip), ResourceType = typeof(Str))]
-public class Option : IOption { }
\ No newline at end of file
+public class Option : OptionBase { }
\ No newline at end of file
diff --git a/src/Lang/Str.Designer.cs b/src/Lang/Str.Designer.cs
index aaf4f04..353b6e2 100644
--- a/src/Lang/Str.Designer.cs
+++ b/src/Lang/Str.Designer.cs
@@ -131,6 +131,15 @@ namespace Dot.Lang {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to 执行命令后保留会话.
+        /// </summary>
+        public static string KeepSession {
+            get {
+                return ResourceManager.GetString("KeepSession", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Local clock offset.
         /// </summary>
@@ -194,6 +203,15 @@ namespace Dot.Lang {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to NTP 服务器标准时钟: {0}.
+        /// </summary>
+        public static string NtpServerTime {
+            get {
+                return ResourceManager.GetString("NtpServerTime", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to 指定的路径“{0}”不存在.
         /// </summary>
diff --git a/src/Lang/Str.en-US.resx b/src/Lang/Str.en-US.resx
index 25c0ec5..564b9db 100644
--- a/src/Lang/Str.en-US.resx
+++ b/src/Lang/Str.en-US.resx
@@ -131,4 +131,10 @@
     <data name="Ip" xml:space="preserve">
         <value>IP tools</value>
     </data>
+    <data name="KeepSession" xml:space="preserve">
+        <value>Keep the session after executing the command</value>
+    </data>
+    <data name="NtpServerTime" xml:space="preserve">
+        <value>NTP server standard clock: {0}</value>
+    </data>
 </root>
\ No newline at end of file
diff --git a/src/Lang/Str.resx b/src/Lang/Str.resx
index 8d28ed4..b91ca60 100644
--- a/src/Lang/Str.resx
+++ b/src/Lang/Str.resx
@@ -60,6 +60,9 @@
     <data name="FileSearchPattern" xml:space="preserve">
         <value>文件通配符</value>
     </data>
+    <data name="KeepSession" xml:space="preserve">
+        <value>执行命令后保留会话</value>
+    </data>
     <data name="TimeoutMillSecs" xml:space="preserve">
         <value>连接NTP服务器超时时间 (毫秒)</value>
     </data>
@@ -121,6 +124,9 @@
     <data name="LocalTimeOffset" xml:space="preserve">
         <value>{0}, 本机时钟偏移: {1} ms</value>
     </data>
+    <data name="NtpServerTime" xml:space="preserve">
+        <value>NTP 服务器标准时钟: {0}</value>
+    </data>
     <data name="LocalTimeSyncDone" xml:space="preserve">
         <value>本机时间已同步</value>
     </data>
diff --git a/src/Option.cs b/src/Option.cs
new file mode 100644
index 0000000..5bac861
--- /dev/null
+++ b/src/Option.cs
@@ -0,0 +1,7 @@
+namespace Dot;
+
+public abstract class OptionBase : IOption
+{
+    [Option('k', "keep-session", HelpText = nameof(Str.KeepSession), Default = false, ResourceType = typeof(Str))]
+    public virtual bool KeepSession { get; set; }
+}
\ No newline at end of file
diff --git a/src/Program.cs b/src/Program.cs
index 19e2623..5e5ac7f 100644
--- a/src/Program.cs
+++ b/src/Program.cs
@@ -12,8 +12,14 @@ Type[] LoadVerbs()
 
 async Task Run(object args)
 {
-    var tool = ToolsFactory.Create(args as IOption);
+    var option = args as OptionBase;
+    var tool   = ToolsFactory.Create(option);
     await tool.Run();
+    if (option!.KeepSession) {
+        Console.WriteLine();
+        Console.WriteLine(Str.PressAnyKey);
+        Console.ReadKey();
+    }
 }
 
 
diff --git a/src/Pwd/Main.cs b/src/Pwd/Main.cs
index 03d138c..d73869f 100644
--- a/src/Pwd/Main.cs
+++ b/src/Pwd/Main.cs
@@ -3,7 +3,7 @@ using TextCopy;
 
 namespace Dot.Pwd;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 {
     private readonly char[][] _charTable = {
                                                "0123456789".ToCharArray() //
diff --git a/src/Pwd/Option.cs b/src/Pwd/Option.cs
index 7e205e5..cb2a9a5 100644
--- a/src/Pwd/Option.cs
+++ b/src/Pwd/Option.cs
@@ -1,7 +1,7 @@
 namespace Dot.Pwd;
 
 [Verb("pwd", HelpText = nameof(Str.RandomPasswordGenerator), ResourceType = typeof(Str))]
-public class Option : IOption
+public class Option : OptionBase
 {
     [Flags]
     public enum GenerateTypes
diff --git a/src/RmBlank/Main.cs b/src/RmBlank/Main.cs
index 2ec8dd9..f2e7be4 100644
--- a/src/RmBlank/Main.cs
+++ b/src/RmBlank/Main.cs
@@ -3,7 +3,7 @@ using NSExt.Extensions;
 
 namespace Dot.RmBlank;
 
-public sealed class Main : Tool<Option>, IDisposable
+public sealed class Main : ToolBase<Option>, IDisposable
 {
     private                 int              _breakCnt;
     private                 bool             _disposed;
diff --git a/src/RmBom/Main.cs b/src/RmBom/Main.cs
index 155867e..28f6961 100644
--- a/src/RmBom/Main.cs
+++ b/src/RmBom/Main.cs
@@ -2,7 +2,7 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace Dot.RmBom;
 
-public sealed class Main : Tool<Option>, IDisposable
+public sealed class Main : ToolBase<Option>, IDisposable
 {
     private                 int              _breakCnt;
     private                 bool             _disposed;
diff --git a/src/Text/Main.cs b/src/Text/Main.cs
index 776226c..ec56fbe 100644
--- a/src/Text/Main.cs
+++ b/src/Text/Main.cs
@@ -5,7 +5,7 @@ using TextCopy;
 
 namespace Dot.Text;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 {
     private ref struct Output
     {
@@ -108,7 +108,5 @@ html-decode:       {o.HtmlDecode}
 
 
         ParseAndShow(Opt.Text);
-        Console.Write(Str.PressAnyKey);
-        Console.ReadKey();
     }
 }
\ No newline at end of file
diff --git a/src/Text/Option.cs b/src/Text/Option.cs
index 90528c6..8f2197b 100644
--- a/src/Text/Option.cs
+++ b/src/Text/Option.cs
@@ -1,7 +1,7 @@
 namespace Dot.Text;
 
 [Verb("text", HelpText = nameof(Str.TextTool), ResourceType = typeof(Str))]
-public class Option : IOption
+public class Option : OptionBase
 {
     [Value(0, HelpText = nameof(Str.TextTobeProcessed), ResourceType = typeof(Str))]
     public string Text { get; set; }
diff --git a/src/Time/Main.cs b/src/Time/Main.cs
index 85a72af..c54dbf2 100644
--- a/src/Time/Main.cs
+++ b/src/Time/Main.cs
@@ -5,7 +5,7 @@ using System.Runtime.InteropServices;
 
 namespace Dot.Time;
 
-public sealed class Main : Tool<Option>
+public sealed class Main : ToolBase<Option>
 {
     private record Server
     {
@@ -217,16 +217,20 @@ public sealed class Main : Tool<Option>
         Console.WriteLine(Str.NtpReceiveDone, _successCnt, _serverCnt, avgOffset.TotalMilliseconds);
 
         if (!Opt.Sync) {
+            if (!Opt.KeepSession) return;
+
+            var waitObj = new ManualResetEvent(false);
             var _ = Task.Run(async () => {
+                var top = Console.GetCursorPosition().Top;
                 while (true) {
+                    Console.SetCursorPosition(0, top);
+                    Console.Write(Str.NtpServerTime, (DateTime.Now - avgOffset).ToString("O"));
+                    waitObj.Set();
                     await Task.Delay(100);
-                    Console.SetCursorPosition(0, Console.GetCursorPosition().Top);
-                    Console.Write(Str.ServerTime, (DateTime.Now - avgOffset).ToString("O"));
-                    Console.Write(@", {0}",       Str.PressAnyKey);
                 }
                 // ReSharper disable once FunctionNeverReturns
             });
-            Console.ReadKey();
+            waitObj.WaitOne();
             return;
         }
 
diff --git a/src/Time/Option.cs b/src/Time/Option.cs
index 401bb0b..5b0d585 100644
--- a/src/Time/Option.cs
+++ b/src/Time/Option.cs
@@ -1,7 +1,7 @@
 namespace Dot.Time;
 
 [Verb("time", HelpText = nameof(Str.TimeTool), ResourceType = typeof(Str))]
-public class Option : IOption
+public class Option : OptionBase
 {
     [Option('s', "sync", HelpText = nameof(Str.SyncToLocalTime), Default = false, ResourceType = typeof(Str))]
     public bool Sync { get; set; }
diff --git a/src/ToLf/Main.cs b/src/ToLf/Main.cs
index 00afacd..e05ef03 100644
--- a/src/ToLf/Main.cs
+++ b/src/ToLf/Main.cs
@@ -2,7 +2,7 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace Dot.ToLf;
 
-public sealed class Main : Tool<Option>, IDisposable
+public sealed class Main : ToolBase<Option>, IDisposable
 {
     private                 int              _breakCnt;
     private                 bool             _disposed;
diff --git a/src/Tool.cs b/src/ToolBase.cs
similarity index 95%
rename from src/Tool.cs
rename to src/ToolBase.cs
index 05496f4..54511f0 100644
--- a/src/Tool.cs
+++ b/src/ToolBase.cs
@@ -1,6 +1,6 @@
 namespace Dot;
 
-public abstract class Tool<TOption> : ITool
+public abstract class ToolBase<TOption> : ITool where TOption : OptionBase
 {
     protected readonly ProgressBarOptions //
         DefaultProgressBarOptions = new() {
@@ -15,7 +15,7 @@ public abstract class Tool<TOption> : ITool
 
     protected TOption Opt { get; }
 
-    protected Tool(TOption opt)
+    protected ToolBase(TOption opt)
     {
         Opt = opt;
     }