In the vaulting events, gymnasts sprint down a 25 metres (82 ft) runway, jump onto a spring filled board or perform a roundoff, or handspring entry onto a springboard (run/ take-off segment), land momentarily, inverted on the hands on the vaulting horse, or vaulting table (pre flight segment), then propel themselves forward or backward, off of this platform to a two footed landing (post flight segment). Every gymnast starts at a different point on the vault runway depending on their height and strength. The post flight segment may include one or more multiple saltos or somersaults, and/or twisting movements. A round-off entry vault, called a Yurchenko, is the most common vault in elite level gymnastics. When performing a yurchenko, gymnasts "round-off" so hands are on the runway while the feet land on the springboard (beatboard). From the roundoff position the gymnast travels backwards and executes a backhandspring so that the hands land on the vaulting table. The gymnast then blocks off the vaulting platform into various twisting and/or somersaulting combinations. The post flight segment brings the gymnast to her feet.
What determines where a vaulter starts on the runway?
their height and strength

High levels of precipitation cause the glaciers to descend to permafrost levels in some areas whereas in other, more arid regions, glaciers remain above about the 3,500 m (11,483 ft) level. The 1,817 square kilometres (702 sq mi) of the Alps covered by glaciers in 1876 had shrunk to 1,342 km2 (518 sq mi) by 1973, resulting in decreased river run-off levels. Forty percent of the glaciation in Austria has disappeared since 1850, and 30% of that in Switzerland.
How much of the glaciation disappeared in Switzerland?
30%

In 1579 a number of the northern provinces of the Low Countries signed the Union of Utrecht, in which they promised to support each other in their defence against the Spanish army. This was followed in 1581 by the Act of Abjuration, the declaration of independence of the provinces from Philip II.
In what year was the Act of Abjuration signed?
1581