関連ワード:  how to add a time to google slides    how to add a clock to google slides    how to add a time limit to google slides    how to add a real time clock to google slides    how to add transition time to google slides    how to add current time to google slides    how to add a digital clock to google slides    how to add a countdown clock to google slides    how to add a working clock to google slides    how to add time to google docs