UNIVERSIDAD DE CALDAS
FACULTAD DE ARTES Y HUMANIDADES
DEPARTAMENTO DE LENGUAS Y LITERATURA
EXAMEN GENERAL DE COMPRENSIÓN LECTORA EN INGLÉS
Formato B
DO NOT WRITE OR MAKE ANY MARKS ON THIS TEST
READING COMPREHENSION: For problems 1 to 40, read the passages, then answer the questions following them according to the information given in each passage.
Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds-any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete for sunlight, nutrients, and water with useful plants.
The global need for weed control has been answered mainly by the chemical industry. Its herbicides are effective and sometimes necessary, but some pose serious problems, particularly if misused. Toxic compounds threaten animal and public health when they accumulate in food plants, ground water, and drinking water. They also harm workers who apply them.
In recent years, the chemical industry has introduced several herbicides that are more ecologically sound. Yet new chemicals alone cannot solve the world’s weed problems. Hence, scientists are exploring the innate weed-killing powers of living organisms, primarily insects and micro organisms.
The biological agents now in use are harmless to humans and are environmentally benign. They can be chosen for their ability to attack selected targets and leave crops and other plants untouched. In contrast, some of the most effective chemicals kill virtually all the plants they come in contact with, sparing only those that are naturally resistant or have been genetically modified for resistance. Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. Chemicals typically must be used several times per growing season.
5. With which of the following statements about the use of chemical agents as herbicides would the author most likely agree?
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