Article: Areas that should not be soldered may be covered with solder resist (solder mask). One of the most common solder resists used today is called "LPI" (liquid photoimageable solder mask).  A photo-sensitive coating is applied to the surface of the PWB, then exposed to light through the solder mask image film, and finally developed where the unexposed areas are washed away. Dry film solder mask is similar to the dry film used to image the PWB for plating or etching. After being laminated to the PWB surface it is imaged and develop as LPI. Once common but no longer commonly used because of its low accuracy and resolution is to screen print epoxy ink. Solder resist also provides protection from the environment.

Question: What solder resist with a four-word name is a popular choice in the industry?
Ans: liquid photoimageable solder mask


Article: A tile mosaic is a digital image made up of individual tiles, arranged in a non-overlapping fashion, e.g. to make a static image on a shower room or bathing pool floor, by breaking the image down into square pixels formed from ceramic tiles (a typical size is 1 in × 1 in (25 mm × 25 mm), as for example, on the floor of the University of Toronto pool, though sometimes larger tiles such as 2 in × 2 in (51 mm × 51 mm) are used). These digital images are coarse in resolution and often simply express text, such as the depth of the pool in various places, but some such digital images are used to show a sunset or other beach theme.

Question: How should the tiles be aligned next to each other?
Ans: in a non-overlapping fashion


Article: A week after the implementation of the no-fly zone, NATO announced that it would be enforced. On 30 April a NATO airstrike killed Gaddafi's sixth son and three of his grandsons in Tripoli, though Gaddafi and his wife were unharmed. Western officials remained divided over whether Gaddafi was a legitimate military target under the U.N. Security Council resolution. U.S. Secretary of Defense Robert Gates said that NATO was "not targeting Gaddafi specifically" but that his command-and-control facilities were legitimate targets—including a facility inside his sprawling Tripoli compound that was hit with airstrikes on 25 April.

Question: What city did NATO bomb on 25 April?
Ans: Tripoli


Article: Since chlorinated hydrocarbon pesticides dissolve in fats and are not excreted, organisms tend to retain them almost indefinitely. Biological magnification is the process whereby these chlorinated hydrocarbons (pesticides) are more concentrated at each level of the food chain. Among marine animals, pesticide concentrations are higher in carnivorous fishes, and even more so in the fish-eating birds and mammals at the top of the ecological pyramid. Global distillation is the process whereby pesticides are transported from warmer to colder regions of the Earth, in particular the Poles and mountain tops. Pesticides that evaporate into the atmosphere at relatively high temperature can be carried considerable distances (thousands of kilometers) by the wind to an area of lower temperature, where they condense and are carried back to the ground in rain or snow.

Question: The movement of pesticides from wawrme to cooler climates is called what?
Ans:
Global distillation