diff --git a/legacy/README.md b/legacy/README.md
index 1f0b4a8..cd94f01 100644
--- a/legacy/README.md
+++ b/legacy/README.md
@@ -1,3 +1,5 @@
 # LCR Connector (Legacy)
 
 在3个元器件内，使用给定元器件数值列表快速找到目标数值元器件的最好拼接方式，支持电阻，电容，电感
+
+执行`uv run lcr-connector --help`来查阅参数手册。
diff --git a/legacy/src/lcr_connector/__init__.py b/legacy/src/lcr_connector/__init__.py
index 66a37f0..afa8cd3 100644
--- a/legacy/src/lcr_connector/__init__.py
+++ b/legacy/src/lcr_connector/__init__.py
@@ -177,12 +177,15 @@ class App:
                 # fetch item and print it
                 item = response[index]
                 print(
-                    "Plan {0}\t{1}\t{2:.2%}".format(
+                    "Plan {0}\tValue: {1}\tDiff: {2} ({3:.2%})".format(
                         index + 1,
                         to_human_readable_value(item.value),
+                        to_human_readable_value(item.difference),
                         item.relative_difference,
                     )
                 )
+                self.__illustrate_circuit(item.circuit)
+
             # print page footer
             print("")
             print("Page {} of {}.".format(current_page + 1, all_page + 1))
@@ -204,15 +207,19 @@ class App:
         :return: The command. It is an instance of `cmd_enum`.
         """
         while True:
-            print("> ", end=None)
-            words = input()
-            words = words.strip()
-            if words in cmd_enum:
+            self.__show_prompt_arrow()
+            words = input().strip()
+            if words == "":
+                continue
+
+            try:
                 return cmd_enum(words)
-            print("Unknown command, please try again.")
+            except ValueError:
+                print("Unknown command, please try again.")
 
     def __accept_device_value(self) -> float:
         while True:
+            self.__show_prompt_arrow()
             words = input()
             value = self.__parse_human_readable_value(words)
             if value is None:
@@ -222,6 +229,7 @@ class App:
 
     def __accept_device_value_tolerance(self, target_value: float) -> float:
         while True:
+            self.__show_prompt_arrow()
             words = input()
 
             if words.endswith("%"):
@@ -238,6 +246,9 @@ class App:
             else:
                 return value
 
+    def __show_prompt_arrow(self) -> None:
+        print("> ", end="")
+
     def __parse_plain_float(
         self, user_value: str, checker: Callable[[float], bool]
     ) -> float | None:
diff --git a/legacy/src/lcr_connector/main.py b/legacy/src/lcr_connector/main.py
index 3f8f202..8b509fb 100644
--- a/legacy/src/lcr_connector/main.py
+++ b/legacy/src/lcr_connector/main.py
@@ -184,7 +184,7 @@ def WriteBoolean(fs, num):
 
 def OutputAsHuman(v):
     if v / 1e-12 < 1e3:
-        return "{:e} n".format(v / 1e-12)
+        return "{:.4f} n".format(v / 1e-12)
     if v / 1e-9 < 1e3:
         return "{:.4f} p".format(v / 1e-9)
     if v / 1e-6 < 1e3:
diff --git a/legacy/src/lcr_connector/query.py b/legacy/src/lcr_connector/query.py
index 6baba5c..04580cf 100644
--- a/legacy/src/lcr_connector/query.py
+++ b/legacy/src/lcr_connector/query.py
@@ -60,7 +60,7 @@ class ResponseItem:
 
         :return: The circuit.
         """
-        return self.circuit
+        return self.__circuit
 
     @cached_property
     def device_count(self) -> int:
@@ -69,7 +69,7 @@ class ResponseItem:
 
         :return: The device count.
         """
-        return self.circuit.device_scale.to_device_count()
+        return self.__circuit.device_scale.to_device_count()
 
     @cached_property
     def value(self) -> float: