I read this background article the other day: Plants called epiphytes grow on other plants. They obtain moisture from the air and make food by photosynthesis. Most epiphytes are ferns or orchids that live in tropical or temperate rainforests (see Figure below ). Host trees provide support, allowing epiphyte plants to obtain air and sunlight high above the forest floor. Being elevated above the ground lets epiphytes get out of the shadows on the forest floor so they can get enough sunlight for photosynthesis. Being elevated may also reduce the risk of being eaten by herbivores and increase the chance of pollination by wind. I am facing a new situation today: While hiking Bob likes to collect plant specimens. Yesterday, he was hiking along a creek, and was specifically looking for epiphytes. Eventually, he found one, and tagged the specimen as specimen A. To compare specimen A with another plant he collected another plant specimen that was not an epiphyte. He tagged that specimen as specimen B. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which specimen would not get moisture from the air, specimen A or specimen B?
Ans: specimen B

I read this background article the other day: The Human Immunodeficiency Virus ( HIV ) is the virus that causes Acquired Immunodeficiency Syndrome ( AIDS ). Most researchers believe that the HIV originated in sub-Saharan Africa during the 20th century. HIV is transmitted by sexual contact and by contact with infected bodily fluids, such as blood, semen, breast milk, and vaginal secretions. It is also passed from mother to fetus. HIV is now a pandemic , with an estimated (as of 2008) 38.6 million people now living with the disease worldwide. It is estimated that AIDS has killed more than 25 million people since it was first recognized in 1981. For further information about HIV/AIDS, see the CDC (Centers for Disease Control and Prevention) web site at http://www.cdc.gov/hiv/resources/factsheets/ . I am facing a new situation today: Dean and Paul both went to volunteered in Africa. They had a blood test when they came back. Paul had been infected with the HIV virus while Dean was healthy and clean. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which friend has a virus that is transmitted by contact with infected semen?
Ans: Paul

I read this background article the other day: Groundwater salinization compromises buffering properties. Vegetation clearance, along with irrigation, causes serious issues. Irrigation increases the water table and mobilizes salts, and vegetation clearance allows it to come in contact with water habitats and vegetation. This stresses species not adapted to high salinity. High levels of salinity reduces water uptake in plants, by causing stomatal closure, reducing photosynthesis. Forests undergo decline in areas of high salinity and shallow groundwater depths because these conditions make them more susceptible to droughts. Forests undergo decline in areas of high salinity and shallow groundwater depths making them more susceptible to droughts. I am facing a new situation today: Two villages were situated on different sides of the hill. Each village has its own approach to agriculture. East village decided to clear the land, by felling many trees and bushes, and set up a vast irrigation system. West village too a more natural approach to food production and applied the edible forest method, and all the permaculture principles over the years. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which village has fewer problems with forest decline?
Ans: West

I read this background article the other day: With shade applications, crops are purposely raised under tree canopies within the shady environment. The understory crops are shade tolerant or the overstory trees have fairly open canopies. A conspicuous example is shade-grown coffee. This practice reduces weeding costs and improves coffee quality and taste. The shade does not necessarily translate into lost or reduced yields. This is because the rate of photosynthesis hardly increases once the light intensity is over about one tenth that of direct overhead sunlight and declines with increasing light intensity. This means that shaded plants can grow well. Planting more than one level of vegetation can increase total photosynthesis and overall yields. I am facing a new situation today: Two coffee farms used different methods to grow coffee. Hill farm grown coffee conventionally, while Valley farm is into shade-grown coffee production. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which farm didn't grow coffee under tree canopies?
Ans: Hill