Brook Trout are not genetically programmed to die after spawning as are the Pacific species of salmon. Spawning is however difficult and dangerous and many fish do die during spawning. The length of the incubation period varies according to the temperature - at lower temperatures the incubation period is longer.
More than half of the total length of the German autobahn network has no speed limit, about one third has a permanent limit, and the remaining parts have a temporary or conditional limit. Some cars with very powerful engines can reach speeds of well over 300 km/h (190 mph).
UK speed limits are shown in mph. With a few exceptions, they are in multiples of 10, ranging from 20 miles per hour (32 km/h) to 70 miles per hour (113 km/h). Unless a lower speed limit is posted on a road, the national speed limit applies, which varies between class of vehicles and the type of road. In a built-up area (usually indicated by street lights), unless signs indicate otherwise, a limit of 30 miles per hour (48 km/h) applies. Other limits are shown in the table.