i have encountered the same error every time，can some one help me ?

C:\odoo> C:\Python27\Scripts\pip.exe install -r requirements.txt    Collecting Babel==2.3.4 (from -r requirements.txt (line 1)) Downloading Babel-2.3.4-py2.py3-none-any.whl (7.1MB) 1% |▌ | 112kB 2.0kB/s eta 0:58:41Exception: Traceback (most recent call last): File "c:\python27\lib\site-packages\pip\basecommand.py", line 215, in main status = self.run(options, args) File "c:\python27\lib\site-packages\pip\commands\install.py", line 324, in run requirement_set.prepare_files(finder) File "c:\python27\lib\site-packages\pip\req\req_set.py", line 380, in prepare_files ignore_dependencies=self.ignore_dependencies)) File "c:\python27\lib\site-packages\pip\req\req_set.py", line 620, in _prepare_file session=self.session, hashes=hashes) File "c:\python27\lib\site-packages\pip\download.py", line 821, in unpack_url hashes=hashes File "c:\python27\lib\site-packages\pip\download.py", line 659, in unpack_http_url hashes) File "c:\python27\lib\site-packages\pip\download.py", line 882, in _download_http_url _download_url(resp, link, content_file, hashes) File "c:\python27\lib\site-packages\pip\download.py", line 603, in _download_url hashes.check_against_chunks(downloaded_chunks) File "c:\python27\lib\site-packages\pip\utils\hashes.py", line 46, in check_against_chunks for chunk in chunks: File "c:\python27\lib\site-packages\pip\download.py", line 571, in written_chunks for chunk in chunks: File "c:\python27\lib\site-packages\pip\utils\ui.py", line 139, in iter for x in it: File "c:\python27\lib\site-packages\pip\download.py", line 560, in resp_read decode_content=False): File "c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\response.py", line 357, in stream data = self.read(amt=amt, decode_content=decode_content) File "c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\response.py", line 324, in read flush_decoder = True File "c:\python27\lib\contextlib.py", line 35, in __exit__ self.gen.throw(type, value, traceback) File "c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\response.py", line 246, in _error_catcher raise ReadTimeoutError(self._pool, None, 'Read timed out.')ReadTimeoutError: HTTPSConnectionPool(host='pypi.python.org', port=443): Read timed out.