For efficiency, you can also select multiple tasks at once and update all of their states in one go. To do this click the small ring at the end of each line to select them.

This will then show an action button at the bottom of the list. Click that and you can update the state of the tasks in one go.

You can use this multiple selection to delete multiple items at once, and also to use the clipboard functions to pick up the tasks and move them to a different location. You do this using the dropdown menu icon at the top of the list.

In there you will see options to act on the selection. There is also a ring icon at the top of the list that can multi-select ALL the items in the list on that page.