Question: Following this battle, Ali fought a battle against Muawiyah, known as the Battle of Siffin. The battle was stopped before either side had achieved victory, and the two parties agreed to arbitrate their dispute. After the battle Amr ibn al-As was appointed by Muawiyah as an arbitrator, and Ali appointed Abu Musa Ashaari. Seven months later, in February 658, the two arbitrators met at Adhruh, about 10 miles north west of Maan in Jordon. Amr ibn al-As convinced Abu Musa Ashaari that both Ali and Muawiyah should step down and a new Caliph be elected. Ali and his supporters were stunned by the decision which had lowered the Caliph to the status of the rebellious Muawiyah I. Ali was therefore outwitted by Muawiyah and Amr. Ali refused to accept the verdict and found himself technically in breach of his pledge to abide by the arbitration. This put Ali in a weak position even amongst his own supporters. The most vociferous opponents in Ali's camp were the very same people who had forced Ali into the ceasefire. They broke away from Ali's force, rallying under the slogan, "arbitration belongs to God alone." This group came to be known as the Kharijites ("those who leave"). In 659 Ali's forces and the Kharijites met in the Battle of Nahrawan. Although Ali won the battle, the constant conflict had begun to affect his standing, and in the following years some Syrians seem to have acclaimed Muawiyah as a rival caliph.
Is there an answer to this question: What group's name means "those who stay"?

Answer: unanswerable

Question: Multi-layer printed circuit boards have trace layers inside the board. This is achieved by laminating a stack of materials in a press by applying pressure and heat for a period of time. This results in an inseparable one piece product. For example, a four-layer PCB can be fabricated by starting from a two-sided copper-clad laminate, etch the circuitry on both sides, then laminate to the top and bottom pre-preg and copper foil. It is then drilled, plated, and etched again to get traces on top and bottom layers.
Is there an answer to this question: Single-layer printed circuit boards have trace layers where?

Answer: unanswerable

Question: International friendlies give team managers the opportunity to experiment with team selection and tactics before the tournament proper, and also allow them to assess the abilities of players they may potentially select for the tournament squad. Players can be booked in international friendlies, and can be suspended from future international matches based on red cards or accumulated yellows in a specified period. Caps and goals scored also count towards a player's career records. In 2004, FIFA ruled that substitutions by a team be limited to six per match in international friendlies, in response to criticism that such matches were becoming increasingly farcical with managers making as many as 11 substitutions per match.
Is there an answer to this question: What do friendlies allow managers to experiment with?

Answer: team selection and tactics

Question: Bacteria, as asexual organisms, inherit identical copies of their parent's genes (i.e., they are clonal). However, all bacteria can evolve by selection on changes to their genetic material DNA caused by genetic recombination or mutations. Mutations come from errors made during the replication of DNA or from exposure to mutagens. Mutation rates vary widely among different species of bacteria and even among different clones of a single species of bacteria. Genetic changes in bacterial genomes come from either random mutation during replication or "stress-directed mutation", where genes involved in a particular growth-limiting process have an increased mutation rate.
Is there an answer to this question: What can cause mutation in bacteria?

Answer:
changes to their genetic material DNA