Choose whether the menu should have a style to control the position of the content, such as left and right.

[ZhangChengLin]

https://getbootstrap.com/docs/4.5/components/forms/#select-menu

1.Choose whether the menu should have a style to control the position of the content, such as left and right.

https://twbs-bootstrap.netlify.app/

2. Is the content of this website updated in real time? Apart from the version number v5.0.0-alpha1, is there a more detailed display? For example, update date.

[mdo]

Select menus don't have this option in HTML, so if you want that, you need to use a dropdown.

And that v5 site is updated as things are merged into master I believe, so it's nearly up to date but not an official v5 alpha.

[ZhangChengLin]

https://getbootstrap.com/docs/4.5/components/forms/#select-menu

<select class="custom-select" dir='rtl'>
  <option selected>Open this select menu</option>
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

Whether the left and right control of the text position can be added is not an arrangement method.

[mdo]

To reiterate, <select> menus cannot have their position controlled. If you want something like a select menu with control over where your menus appears, you need to use our dropdown component: https://getbootstrap.com/docs/4.5/components/dropdowns/#examples.

[ZhangChengLin]

select {
direction: rtl;
}
select option {
direction: ltr;
}