Which of the following is a cause of the challenges to Social Security? a. economic depression c. ageism b. longer life expectancies d. increasing dependency ratio

Why are gold and platinum used for jewelry

Pls will give brainlist if correct

You want to test the hypothesis that smoking cigarettes increases the risk of lung cancer. in your experiment, you take 100 people of various ages and genders for each of your groups. one group smokes. the other group does not smoke. the group that does not smoke is called the group