Please help me with these questions. Please answer ASAP

Q-Explain the difference between single-mode and multi-mode fiber. Then, identify the main use of each mode type. Finish your discussion with which mode is the most preferred in today's networks and explain why.

Q2- by using diagram fill in the blanks

Q3- please match the correct answers

Using the network diagram to fill in the blanks. If device 2513A and device 2513B want to communicate with each other, device 2513A must use as its default gateway and device 2513B must use as its default gatway. 10.1.1.2 FaE0/1 10.2.2.1 FaE0/0 (PIX NATs to 10.99.99.12) Device 2513A 10.2.2.2 Router 2621 PIX 10.1.1.1 (inside) 10 99.99.1 (outside) 10.2.2.x (IP) AA (IPX) Network 10.3.3.1 10.99.99.2 (inside) E0/1 (outside) E0/0 Router 3660 Device 2513B 10.3.3.2 10.3.3.x (IP) CC (IPX) Network Match the following DNS terms with their respective definition. CNAME name of an IP address PTR Record identifies hosts with specif MX Record holder for arbitrary text inf NS Record specifies the mail-handling TXT Record the name of the authoritat SRV Record an alias of a hostname A Record the opposite of an A Recon AAAA Record IPv6 version of an A Recor