某同学在做研究弹簧的形变与外力的关系实验时，将一轻弹簧竖直悬挂让其自然下垂，测出其自然长度L₀；然后在其下部施加外力F，测出弹簧的总长度L，改变外力F的大小，测出几组数据，作出外力F与弹簧总长度L的关系图线如图所示．（本实验过程中未超出弹簧的弹性限度）．由图可知该弹簧的自然长度为____m；该弹簧的劲度系数为____N/m．（计算结果均保留两位有效数字）

    Do you know 2022World Cup will be held in Qatar（卡塔尔）．And FIFA（国际足联） has made a big decision．The 2022Qatar World Cup will be held in November and December．It is the first time FIFA has moved the event from its traditional summer to winter．

    According to the decision，the 2022World Cup will start on November 21．The final will take place on December18，one week ahead of Christmas．The tournament will last 28days，half a week shorter than usual．

    FIFA said，"This is an important step for us．December18，2022is a Sunday，and it's National Day in Qatar，so it fits perfectly．"

    Many people disagree that Qatar has the chance to held the 2022World Cup，since summer temperatures is very high﹣sometimes，the temperature may be about 50℃．So the country has an idea to move it to winter．At last FIFA gave the chance to Qatar．

    Although the change is good for the players，there is still much opposition．The biggest opposition comes from the major European leagues（欧洲联赛），because the new time will be just Europe's club season．FIFA said they will try their best to make things go well．