save project

my_tree.py

@@ -9,7 +9,7 @@ w.bgcolor('wheat')
 pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
-
+pen.down
 
 def tree(n):
     if n >= 0:
@@ -28,7 +28,7 @@ def tree(n):
         tree(n-10*length)       
         pen.left(60*angle)
         tree(n-10*length)
-        tree.right(30*angle)
+        pen.right(30*angle)
         pen.up()
         pen.backward(n)
         pen.down()