Explanation:

Statement 1: It is not a straight line. For parts of its length, the IDL follows the meridian of 180° longitude, roughly down the middle of the Pacific Ocean. To avoid crossing nations internally, the IDL deviates west around the US Aleutian Islands, separating them from islands in the far east of Russia, and further south, it deviates east around various island nations in the Pacific such as Kiribati, Samoa, Tonga and Tokelau.
Statement 2: A person who goes around the world from east to west (the same direction as Magellan's voyage) would gain or set their clock back one hour for every 15° of longitude crossed, and would gain 24 hours for one circuit of the globe from east to west if they did not compensate by setting their clock forward one day when they crossed the IDL. In contrast, a west-to-east circumnavigation of the globe loses an hour for every 15° of longitude crossed but gains back a day when crossing the IDL. The IDL must therefore be observed in conjunction with the Earth's time zones: on crossing it in either direction, the calendar date is adjusted by one day.
Statement 3: It passes through the middle of the Pacific Ocean.