Safety measures to be observed when using the computer include all of the following except

Dropping liquids in the computer room is not a safety measure to be observed when using the computer. This is because liquids can cause damage to the computer's internal components and can also pose a safety risk, such as the risk of electrical shock. On the other hand, the other options listed are safety measures to be observed when using the computer. Using an anti-glare protector can help reduce eye strain and fatigue, maintaining a proper sitting posture can help prevent back and neck pain, and keeping the environment dust-free can prevent damage to the computer's internal components.