While in the Sequence area, if you hold the left mouse button and move the cursor, you will activate the selection mode. By moving the cursor you can adjust the size of the selection. Also you can use the Shift modifier for selecting. Select a first row, hold Shift and select a last row. All the rows between the first and the last row will be selected. You can move the selection by drag and drop.
Releasing the mouse button will result in exiting the selection mode.
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