Final answer:
A systematic instructional practice for developing oral language skills is the use of sign language in conjunction with spoken language.
Step-by-step explanation:
A systematic instructional practice for developing oral language skills is the use of sign language in conjunction with spoken language. This strategy involves teaching children both signs (such as those of American Sign Language) and spoken words for objects. By using both forms of language, the brain is engaged in different ways, providing deeper cognitive reinforcement and increasing the likelihood of recall. For example, parents teaching signs to their children alongside spoken words can enhance their oral language development.