Content of the Page is not Showing

Hey, I am facing a serious problem.
When I click on About or Process link on the Nav Bar the content of other page does not showing. I inspect the page in chrome content was still there but it is not showing.
Its urgent so can anybody have an idea about it.
please let me know

Here is the website Link

Here is my site Read-Only: LINK
(how to share your site Read-Only link)