VSTEP Reading Mock Test 01

Popularized by its inclusion on the typical gap-year agenda for high school students after graduation and regarded as another tick on the CV, volunteering has become a trendy way for wealthy westerners to give back to less fortunate communities. However, despite good intentions from participants, volunteering abroad has attracted substantial criticism over the past few years.

(A) "Are the volunteers actually providing any benefits to the destination countries?" asks Mark Watson, the Executive Director of Tourism Concern, a charity campaigning on ethical tourism issues. More often than not, the answer is unquestionably no.

The demand for volunteer spots in developing countries has led to hundreds of commercial volunteering organizations springing up. Many claim to have noble intentions but pocket the money for profit and send volunteers on unsatisfying, purpose-built placements.

(B) Rather than benefiting local communities, voluntourism can have negative impacts, a number of studies have highlighted. These range from volunteers taking local jobs to child trafficking, where young children are stolen from their families and placed into 'orphanages' to fuel the demand for volunteer placements. These kidnapped children are then subjected to deliberately poor living conditions to elicit higher donations from visiting westerners.

While Watson acknowledges there are companies out there who employ good practices, it's a change in the mindset of would-be volunteers he'd most like to see.

"I talk to a lot of people who say they want to dig wells in Africa. I say what Africa has got quite a lot of is unskilled labor; there are a lot of people out there that can dig wells. The idea that you, as an unskilled worker, have got anything really useful that you can add is slightly arrogant and sort of imperialistic in some ways—white people going out to Africa to help the Africans. I think it's mostly about getting people to be realistic; you're just doing it for yourself, it's a holiday. You're not really going to do anything particularly worthwhile, and that's quite a hard message to get across," says Watson.

Kate Stefanko, Placement Director at People and Places, agrees to an extent, but she thinks volunteering abroad can be beneficial to all concerned if it is done right. "We believe that a carefully placed, thoroughly screened, well-prepared, skilled volunteer can—and does—have a positive impact," says Stefanko. All volunteers through People and Places have to apply for a position. Then, if accepted, the volunteer is matched with an upcoming project that can benefit from their skill set. As a result, well-run efforts can absolutely develop a level of social interaction and understanding that is profound.

Bees are an intricate part of the pollination process. Honeybees account for more than 80 percent of the pollination that most vegetables, fruits, and legumes need, the University of Minnesota Extension states on its website. Normally found on spring, summer, and fall blossoms, bees use the nectar and pollen they collect for sustenance and hive warmth. In fact, freezing temperatures kill bees if they don't warm themselves within their hive.

(A) Bees are cold-blooded; they rely on outside temperatures to regulate their body heat. As a result, honeybees typically emerge from their protective hives during the daytime, commonly between 8 a.m. and 5 p.m. They fly only when the air temperature is above 13 to 16 degrees Celsius. Freezing temperatures essentially lock bee muscles in place; their wings cannot beat correctly for proper and safe flight. Being in dropping temperatures causes exposure and normally leads to death. Freezing temperatures also affect nectar viscosity. Even if bees could fly in cold temperatures, flower nectar may be too thick for them to collect or the flowers may be closed in response to the weather.

(B) A typical beehive maintains an interior temperature of about 33 to 35 degrees Celsius. When freezing temperatures arrive, bees can survive only if they remain inside the hive in a large group, much like penguins huddling together during winter. Clustering, however, does not generate enough heat to combat death from freezing. Bees consume the honey reserves within the hive to create more heat. If bees leave the hive during a cold period, they usually freeze before returning.

(C) Bees use freezing temperatures to their advantage for hive population control. Specific bees, called drones, are used simply for reproduction; they allow the queen bee to create numerous eggs during the warm months. By autumn, the drones are not needed. Worker bees remove them from the hive. With cold weather setting in, exposed drones freeze, effectively controlling the hive's population. A hive may lose up to one-half of its population during winter months. This constant hive rejuvenation allows the queen to produce more worker bees for increased nectar and pollen collection.

(D) Your home may have structural cavities that bees find desirable for a hive. If you find a hive hidden in your home's walls, do not attempt to disturb it. Any vibration or disturbance to the colony easily agitates the bees, causing possible stings and major injury or death to humans with allergic reactions. Contact a professional bee removal company. It may be possible for the professionals to use freezing weather as a hive removal strategy. They can open the hive to the freezing elements. That process avoids the use of pesticides and ensures the safety of your home.

The continents may have first risen high above the oceans of the world about 3 billion years ago, researchers say. That's about a billion years earlier than geoscientists had suspected for the emergence of a good chunk of the continents.

Earth is the only known planet whose surface is divided into continents and oceans. Currently, the continents rise an average of about 2.5 miles (4 kilometers) above the seafloor.

The continents are composed of a thick, buoyant crust that's about 21 miles (35 km) deep, on average, whereas the comparatively thin, dense crust of the ocean floor is only an average of about 4 miles (7 km) thick. Because the continents are so thick and buoyant, they are less likely to get dragged downward. That's why so many ancient continental rocks have survived in the Earth's crust. Still, much about the earliest days of the continents, and when and how they formed, remains hotly contested.

"Earth's surface is continually being reworked by tectonics and agents of erosion, so what may have formed long ago may no longer be present," said geologist Cin-Ty Lee at Rice University in Houston, who was not involved in the current study.

(A) To shed light on the origins of continents, isotope geochemist Bruno Dhuime at the University of Bristol in England and his colleagues analyzed more than 13,000 samples of rocks from the continental crust. Some of these samples were more than 4 billion years old.

Prior research suggested the first 2 billion years of Earth's 4.5-billion-year history were dominated by volcanic activity that generated the kind of crust now seen on the seafloor. Continent-like crust, which is thick and rich in silica, was thought to only have emerged in great volumes in the past 2 billion years. Determining what the earliest continental crust was like and when it formed can be tricky, because Earth's crust has melted and mixed together over and over again.

The researchers found that when magma cools and crystallizes, the remaining molten rock becomes enriched in silica and rubidium, but less so in strontium. The relative amounts of rubidium and strontium are therefore linked with the amount of silica in rock, and so could be used to extrapolate when in the modern era thick, silica-rich continental crust emerged.

(B) The researchers found that modern, silica-rich continental crust first appeared about 3 billion years ago. The thick, buoyant nature of these chunks of crust would have made them rise high above what became the seafloor, Dhuime and his colleagues note online June 22 in the journal Nature Geoscience.

(C) "They are showing when continents actually emerged from the oceans," said Lee, who wrote an accompanying news article in Nature Geoscience. "Continents certainly existed early in Earth's history, but perhaps many were submerged."

It remains uncertain why continental crust made its first appearance about 3 billion years ago. One possibility is the onset of plate tectonics—when the plates of rock making up the planet's exterior began moving slowly over the Earth's mantle layer. Plate tectonics would have resulted in wet rock getting shoved down into Earth's interior, eventually helping to form silica-rich magmas that make up much of the continental crust.