The giraffes spend more than 23 hours a day a.....e .
The giraffes spend more than 23 hours a day ..... .
Adult humans need about ...... hours' sleep.
Adult humans need about seevn hours' sleep.
Between the ages 11 and 17, we need between ..... hours.
Between the ages 11 and 17, we need between 9 and 11 hours.