Are you talking about the "Activities" menu where two elements are appearing side-by-side? If so, the elements are not in a single listing, they're two separate elements being displayed side-by-side. Your li elements are being displayed as "list-item", maybe you could try changing this to block or inline-block.
One thing when I click on menu page get move why this happened ?
I don't quite understand the question, but I think you're talking about the fact that the page sometimes appears to "jerk" left and right when you click a menu item.
Has no vertical scroll bars on it, so when a new page is loaded that does have scroll bars, the content appears to get moved left and right. In order to fix this problem, you can set a min-height for your body and html like so:
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