Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 39 to 43.
Temperatures in the Middle East have exceeded 50°C this summer. In the United Arab Emirates (UAE), a heat wave brought the highest temperatures on record for that period of the year. Meanwhile, rainfall is limited to a few millimeters per year. However, several videos have appeared on social networks showing downpours in the area. This is why many have suggested that the United Arab Emirates created artificial rainfall.
Cloud seeding is a weather manipulation practice that has been around for 80 years. It is a form of geoengineering that is often the subject of controversy because its effectiveness remains questionable. It is released by substances such as silver iodide in the cloud, which catalyzes the condensation of water droplets and produces artificial rain.
Silver iodide acts as a "scaffold" to which water molecules can attach until they become so heavy that they fall to the Earth's surface. In this way, simple clouds could theoretically transform into true storms, capable of resisting drought.
In the United States, artificial rain generation was also used in the military before it was banned by the United Nations. However, its effectiveness in conflict has never been proven. Weather manipulation is used to prevent violent storms from breaking through the clouds. Starting in 1990, the UAE launched a government-funded research center dedicated to cloud seeding.
