To unhide the hidden rows, please refer to the shortcut Ctrl+Shit+9 if you like using shortcut or follow the steps below for details:
Step 1: Select the rows between the hidden row;
Step 2: Right-click and select "Unhide" from the dialog box.
Step 3: The hidden row will show up.
Alternatively, please use the commands from the ribbon:
Step 1: Select the rows between the hidden row;
Step 2: Click the "Home" Tab from the ribbon;
Step 3: Select "Unhide Rows" from the "Hide & Unhide" command;
Step 4: The hidden row will appear.