1. A researcher is investigating if the medicine “AIDSCURE” is able to reduce the immune system dysfunction and cancer symptoms affiliated with HIV+. He gives 500 people 100mg of the drug daily, and 500 people a sugar-pill placebo daily. After a 6-month trial he measures the reduction of immune system dysfunction and cancer symptoms. What is the independent and dependent variable?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.