diff --git a/history/003a_legs/src/main/java/com/github/drinkjava2/frog/brain/organ/LogicAnd.java b/history/003a_legs/src/main/java/com/github/drinkjava2/frog/brain/organ/LogicAnd.java
new file mode 100644
index 0000000..df23f68
--- /dev/null
+++ b/history/003a_legs/src/main/java/com/github/drinkjava2/frog/brain/organ/LogicAnd.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2018 the original author or authors. 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
+ * applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
+ * OF ANY KIND, either express or implied. See the License for the specific
+ * language governing permissions and limitations under the License.
+ */
+package com.github.drinkjava2.frog.brain.organ;
+
+import com.github.drinkjava2.frog.Frog;
+import com.github.drinkjava2.frog.brain.Cell;
+import com.github.drinkjava2.frog.brain.Organ;
+import com.github.drinkjava2.frog.brain.Output;
+
+/**
+ * LogicAnd has a "AND" logic, i.e. if 2 cells active it at same time, it active
+ * 
+ * 与门
+ */
+public class LogicAnd extends Organ { // 随意布置一些"与门"在脑里,至于能不能被选中，就听天由命了
+	private static final long serialVersionUID = 1L;
+
+	@Override
+	public void active(Frog f) {
+		Cell c1 = null;
+		Cell c2 = null;
+		for (Cell cell : f.cells) {
+			if (cell.energy > organActiveEnergy)
+				for (Output output : cell.outputs) { //
+					if (this.nearby(output)) {
+						if (c1 == null)
+							c1 = cell;
+						else {
+							c2 = cell;
+							break;
+						}
+					}
+				}
+		}
+		if (c2 != null) {// 同时找到两个cell激活同一个区了，开始实施与门的逻辑，激活其它与这个器官相连的神经
+			c1.organ.fat++;
+			c1.energy -= 10;//
+			c2.organ.fat++;
+			c2.energy -= 10;//
+			activeOtherCells(f);
+		}
+	}
+
+}