diff --git a/README.md b/README.md
index 728d630..acb0a30 100644
--- a/README.md
+++ b/README.md
@@ -85,6 +85,7 @@ langs = ["python", "java", "Julia", "C++"]
 def data2chat(msg):
     chat = Chat()
     chat.user("请用语言 %s 打印 hello world" % msg)
+    # 注意，这里不需要 getresponse 而交给异步处理
     return chat
 
 async_chat_completion(langs, chkpoint="async_chat.jsonl", nproc=2, data2chat=data2chat)
diff --git a/README_en.md b/README_en.md
index 7b4a42d..761b9cd 100644
--- a/README_en.md
+++ b/README_en.md
@@ -60,6 +60,7 @@ def msg2chat(msg):
     chat = Chat()
     chat.system("You are a helpful translator for numbers.")
     chat.user(f"Please translate the digit to Roman numerals: {msg}")
+    # We need to call `getresponse` here to get the response
     chat.getresponse()
     return chat
 
@@ -80,6 +81,7 @@ langs = ["python", "java", "Julia", "C++"]
 def data2chat(msg):
     chat = Chat()
     chat.user("Please print hello world using %s" % msg)
+    # Note that we don't need to call `getresponse` here, and leave it to the asynchronous processing
     return chat
 
 async_chat_completion(langs, chkpoint="async_chat.jsonl", nproc=2, data2chat=data2chat)
diff --git a/chattool/__init__.py b/chattool/__init__.py
index faf0754..c80b1ef 100644
--- a/chattool/__init__.py
+++ b/chattool/__init__.py
@@ -2,7 +2,7 @@
 
 __author__ = """Rex Wang"""
 __email__ = '1073853456@qq.com'
-__version__ = '3.0.1'
+__version__ = '3.1.0'
 
 import os, sys, requests
 from .chattool import Chat, Resp
@@ -25,12 +25,12 @@ def load_envs(env:Union[None, str, dict]=None):
         for key, value in env.items():
             os.environ[key] = value
     # else: load from environment variables
-    api_key = os.environ.get('OPENAI_API_KEY')
-    base_url = os.environ.get('OPENAI_API_BASE_URL', "https://api.openai.com")
-    api_base = os.environ.get('OPENAI_API_BASE', os.path.join(base_url, 'v1'))
+    api_key = os.getenv('OPENAI_API_KEY')
+    base_url = os.getenv('OPENAI_API_BASE_URL') or "https://api.openai.com"
+    api_base = os.getenv('OPENAI_API_BASE', os.path.join(base_url, 'v1'))
     base_url = request.normalize_url(base_url)
     api_base = request.normalize_url(api_base)
-    model = os.environ.get('OPENAI_API_MODEL', "gpt-3.5-turbo")
+    model = os.getenv('OPENAI_API_MODEL', "gpt-3.5-turbo")
     return True
 
 def save_envs(env_file:str):
diff --git a/setup.py b/setup.py
index 20bb558..a0286c9 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@
 with open('README.md') as readme_file:
     readme = readme_file.read()
 
-VERSION = '3.0.1'
+VERSION = '3.1.0'
 
 requirements = [
     'Click>=7.0', 'requests>=2.20', "responses>=0.23", 'aiohttp>=3.8',