2:36How do you become an astronaut?The competition is tough and the standards are high. Applicants to become astronauts not only have to enjoy learning new things. They also have to be very well-organized and able to cope well with stress. This viewer question comes from Aya S. in Egypt.
2:16How does a desalination plant work?Two different processes are used to obtain freshwater from saltwater – distillation and reverse osmosis. It takes around 100 liters of seawater to produce 45 liters of drinking water. Our viewer question this time comes from Richard Z. in Colombia.
2:18What is noise?Noise is sounds that bothers us. That can be sound that is too loud or shrill, or sound that lasts too long. Sound protection can help a lot. We answer a viewer question from Pakisho M. from South Africa.