Q: As time passes, the number of HIV copies keeps increasing, while the number of helper T cells keeps decreasing. The graph in Figure below shows how the number of T cells typically declines over a period of many years following the initial HIV infection. As the number of T cells decreases, so does the ability of the immune system to defend the body. As a result, an HIV-infected person develops frequent infections. Medicines can slow down the virus but not get rid of it, so there is no cure at present for HIV infections or AIDS. There also is no vaccine to immunize people against HIV infection, but scientists are working to develop one. Jacob recently contracted the HIV virus and is going to his first support meeting. While there, he meets Dan and strikes up a conversation with him. Dan says that he has had HIV for over a decade at this point and has learned ways to live with it. He is able to give Jacob some good advice on how to handle things and Jacob is very grateful to have someone to talk with. Is Dan's immune system weaker or stronger than Jacob's?
A: weaker

Q: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. Its rate of loss has slowed with restrictions on pollutants, but it is still at risk. Two teams of researchers studied the environment in Antarctica. Team Black studied air pollution and the ozone layer, Team Red studied the water. Which team observed higher levels of UV reaching Earth?
A: Black

Q: During mid-summer (July in the northern hemisphere), the westward-moving trade winds south of the northward-moving subtropical ridge expand northwestward from the Caribbean into southeastern North America. When dust from the Sahara moving around the southern periphery of the ridge within the belt of trade winds moves over land, rainfall is suppressed and the sky changes from a blue to a white appearance, which leads to an increase in red sunsets. Its presence negatively impacts air quality by adding to the count of airborne particulates. Over 50% of the African dust that reaches the United States affects Florida. Since 1970, dust outbreaks have worsened because of periods of drought in Africa. There is a large variability in the dust transport to the Caribbean and Florida from year to year. Dust events have been linked to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s. Similar dust plumes originate in the Gobi Desert, which combined with pollutants, spread large distances downwind, or eastward, into North America.There are local names for winds associated with sand and dust storms. The Calima carries dust on southeast winds into the Canary islands. The Harmattan carries dust during the winter into the Gulf of Guinea. The Sirocco brings dust from north Africa into southern Europe because of the movement of extratropical cyclones through the Mediterranean. Spring storm systems moving across the eastern Mediterranean Sea cause dust to carry across Egypt and the Arabian peninsula, which are locally known as Khamsin. The Shamal is caused by cold fronts lifting dust into the atmosphere for days at a time across the Persian Gulf states. Jennifer is looking to move to a new city. She has always wanted to live in a coastal town, and she has narrowed her options down to two. She is looking to live in either Malarn or Trainlan. Malarn is known for its peppersteaks and its active nightlife. Malarn also regularly gets a large amount of dust in the air from a desert located across the ocean. Trainlan has a very famous art museum in its city, and being an art fanatic, that greatly appeals to Jennifer. She is planning to take a trip to both cities sometime in the near future to see them in person before making her decision. Which city is worse for Jennifer's health?
A: Malarn

Q: HIV , or human immunodeficiency virus, causes AIDS. AIDS stands for "acquired immune deficiency syndrome." It is a condition that causes death and does not have a known cure. AIDS usually develops 10 to 15 years after a person is first infected with HIV. The development of AIDS can be delayed with proper medicines. The delay can be well over 20 years with the right medicines. Today, individuals who acquire HIV after 50 years of age can expect to reach an average human life span. Tom and Andy are two old friends. Tom was infected with HIV 20 years ago, and Andy has been helping him ever since. Andy is as healthy as an ox. Which friend doesn't have a disease without cure?
A:
Andy