This is an A. <span>observational study. They are observing the use of cell phones differs between people with or without cancer.
Happy studying ^-^</span>
Answer:

Step-by-step explanation:
If you have the same denominator, you can just subtract the numerators normally and carry over the denominator.
Answer:
5.5 ft
Step-by-step explanation:
therefore if you cut 11 in half you get 5.5
Answer 20 I just did that question