A scope is a term used to define a range of IP addresses available to assign using DHCP. DHCP stands for Dynamic Host Configuration Protocol, and it is a protocol that automatically assigns IP addresses and other network configuration parameters to devices on a network. A scope defines the start and end IP addresses, as well as other options, such as subnet mask, default gateway, and DNS servers.

Thermal paste is a substance that fills in any gaps between a CPU and its heat sink, which is a device that dissipates heat from the CPU. Without adequate thermal paste, the CPU may overheat and cause the system to shut down automatically to prevent damage. This is especially likely when running 4K video or games, which are more demanding and generate more heat. The technician should check if the CPU heat sink was attached properly and apply enough thermal paste to ensure good contact and heat transfer. Reference: https://partners.
comptia.org/docs/default-source/resources/a-core-series-combined-content-guide (page 28)

It is designed to protect an organization's network infrastructure and data from unauthorized access, while allowing legitimate traffic to pass through. Firewalls can be configured to enforce security policies that block certain types of traffic, limit access to specific network resources, and prevent attacks such as malware and phishing.
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet. Firewalls are used to implement network security policies for an environment by controlling access to the network and protecting it from unauthorized access.
A firewall is used to implement network security policies. It monitors incoming and outgoing traffic based on predetermined security rules and can block traffic that does not meet the defined criteria. References:
CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition by Mike Meyers (Chapter 6, page 243)

Vertical or horizontal lines-Marks that appear in the same place (referred to as repetitive defects) are often due to dirty feed rollers (note that there are rollers in the toner cartridge and fuser unit too) or a damaged or dirty photosensitive drum.
Vertical streaks on a laser printer output are usually caused by a damaged or worn-out drum, which is responsible for transferring toner to the paper. If the drum is damaged, toner may accumulate on certain parts of the drum, leading to streaks on the printed output. References: CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition, Chapter 15

The minimum cable category that could be used to support a 10Gbps throughput is Cat 6a. Cat 6a cable is required with 10 Gigabit Ethernet for reliable performance with cable lengths up to 100 metres. However, lower-specification cables can often be successfully used, particularly with the shorter cable lengths required in a typical home123.