According to General Order 7, what is one thing a sentry is instructed not to do?

The correct answer indicates that a sentry is instructed not to engage in conversation with others. This guideline is essential for maintaining discipline and focus on the task at hand. A sentry's primary responsibility is to remain vigilant and attentive to their surroundings. Engaging in conversations can distract them from their duties, potentially compromising security and safety. By minimizing distractions, the sentry can effectively monitor for any unauthorized activities or threats.

The other options, while relevant to a sentry's duties, either encourage appropriate actions like assisting those in need or highlight the importance of following orders and maintaining presence at their post. However, interaction with others can lead to a lapse in attention, which is why this practice is explicitly discouraged.