Which of the following is true of the cerebral hemispheres of the human brain?-The cerebral hemispheres account for about 83% of total brain mass.-Nearly the entire surface of the cerebral hemispheres is marked by elevated ridges called sulci.--Nearly the entire surface of the cerebral hemispheres is marked by shallow grooves called gyri.The longitudinal fissure separates the cerebral hemispheres from the cerebellum.