designing the ventilation systems to prevent any further spread of disease
The main factors contributing to health-related problems during flight that are mentioned in the passage are the confined space in which a passenger has to sit and inadequate ventilation
poor safety instructions handed to the passengers by the cabin crew of the aircraft
the absence of any supply of liquid refreshment served while on board an aircraft
passengers not taking enough exercise before boarding a long flight
106 FROM HASHSHASHIN TO ASSASSIN The adoption of assassination as a political weapon derives from the Islamic world of the 11th century. A secret order of Muslims was founded in Persia in about 1090 by a man named Hasan-i-Sabbah. After gaining control of a mountain fortress near the Caspian Sea, Hasan founded a sect to fight his political enemies by means of murder. Hasan and his followers were known as Nizaris and belonged to the Isma'ili branch of Shi'i Islam. For two centuries this secret organization terrorized the Middle East. Hasan, who gained the nickname "Old Man of the Mountain" from his fortress hideaway, is said to have given his followers a vision-inducing drug called hashish, made from Indian hemp. The visions of Islamic paradise brought on by the drug persuaded his disciples that they would have a glorious afterlife if they followed Hasan's orders and killed his enemies. The killers were called Hashshashin, the plural of an Arabic word meaning "one who smokes hashish." This name was eventually corrupted into its present form, assassin.