1. B. PC power supplies support 110V input, 220V input, or both. Dual-voltage power supplies normally have a selector that allows control of which voltage to use in the proper environment.
2. B. 1394—an IEEE serial bus interface standard also know as FireWire.
1284—IEEE standard for faster throughput and bidirectional data flow is an enhanced parallel interface for PCs. It was used primarily for connecting printers and scanners, but USB is now used more often than parallel connections.
3. D. USB 1.0 maximum of 1.5 for low-speed devices and 12 Mb/s full-speed devices
USB 2.0 maximum 480 Mb/s for high-speed devices
USB 3.0 480 Gb/s for super-speed devices
4. D. A keyboard, ...