I've got an error  after install requirement text when  i install odoo13 on ubuntu 18.04.

What should i do?

Please help me , sir.

{ error: command 'x86_64-linux-gnu-gcc' failed with exit status 4

Command "/opt/odoo13/odoo-venv/bin/python3 -u -c "import setuptools, tokenize;__file__='/t

mp/pip-build-gxsxrk2g/lxml/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.re

ad().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --reco

rd /tmp/pip-li36s1hf-record/install-record.txt --single-version-externally-managed --compi

le --install-headers /opt/odoo13/odoo-venv/include/site/python3.6/lxml" failed with error 

code 1 in /tmp/pip-build-gxsxrk2g/lxml/  }  

Thank you..........