Final answer:
A child with a cleft palate has nasal emission due to air escaping through the opening caused by the incomplete fusion of the two halves of the hard palate.
Step-by-step explanation:
A child with cleft palate has nasal emission when they speak because of air escaping through the opening. A cleft palate is a developmental defect where the two halves of the hard palate do not completely come together and fuse at the midline, leaving a gap between them. This gap allows for communication between the nasal and oral cavities, causing air to escape through the opening during speech.