Final answer:
Social media browsing and file sharing are two online activities that carry high security risks, potentially exposing personal information and increasing the chance of encountering malicious software.
Step-by-step explanation:
The two online activities that pose high security risks are social media browsing and file sharing. When engaging in social media browsing, users may inadvertently expose personal information to a wide audience or fall victim to phishing and scams.
File sharing, particularly on unsecured or pirated platforms, can lead to downloading malicious software that can compromise a user’s system and personal data. It is important for individuals to exercise caution and employ protective measures such as using strong passwords, enabling two-factor authentication, and being vigilant about the types of information shared online to enhance their online privacy and security.