[Q]: Extract the answer to the question from the following context. Question: How can you decipher data in the middle of a CD? Context: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.
****
[A]: swing arm

[Q]: Extract the answer to the question from the following context. Question: What is not typically included in an external drive: translating device, or ExpressCard? Context: Firstly conceived and still used today for optical storage devices (CD-RW drives, DVD drives, etc.), several manufacturers offer external portable USB hard disk drives, or empty enclosures for disk drives. These offer performance comparable to internal drives, limited by the current number and types of attached USB devices, and by the upper limit of the USB interface (in practice about 30 MB/s for USB 2.0 and potentially 400 MB/s or more for USB 3.0). These external drives typically include a "translating device" that bridges between a drive's interface to a USB interface port. Functionally, the drive appears to the user much like an internal drive. Other competing standards for external drive connectivity include eSATA, ExpressCard, FireWire (IEEE 1394), and most recently Thunderbolt.
****
[A]: ExpressCard

[Q]: Extract the answer to the question from the following context. Question: When were people first seen in the bottom part of Namibia? Context: The dry lands of Namibia were inhabited since early times by San, Damara, Nama and, since about the 14th century AD, by immigrating Bantu who came with the Bantu expansion from central Africa. From the late 18th century onwards, Orlam clans from the Cape Colony crossed the Orange River and moved into the area that today is southern Namibia. Their encounters with the nomadic Nama tribes were largely peaceful. The missionaries accompanying the Orlams were well received by them, the right to use waterholes and grazing was granted against an annual payment. On their way further northwards, however, the Orlams encountered clans of the Herero tribe at Windhoek, Gobabis, and Okahandja which were less accommodating. The Nama-Herero War broke out in 1880, with hostilities ebbing only when Imperial Germany deployed troops to the contested places and cemented the status quo between Nama, Orlams, and Herero.
****
[A]: late 18th century

[Q]: Extract the answer to the question from the following context. Question: What is different between a bacteria and a human? Context: The genome size, and the number of genes it encodes varies widely between organisms. The smallest genomes occur in viruses (which can have as few as 2 protein-coding genes), and viroids (which act as a single non-coding RNA gene). Conversely, plants can have extremely large genomes, with rice containing >46,000 protein-coding genes. The total number of protein-coding genes (the Earth's proteome) is estimated to be 5 million sequences.
****
[A]:
The genome size, and the number of genes it encodes