What kind of new therapies are scientists working on to treat cystic fibrosis? Select all that apply.

A - gene therapies to fix the CFTR gene
B - gene editing to remove the CFTR protein
C - injections to add water directly to the mucus
D - inhalers to deliver CFTR to the cells

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.