15．
Ready，Set，Jump!
For skydivers，the sky isn't the limit．It's just the beginning．Thousands if people try skydiving each year．Some only jump once，while others go on to experience lifelong adventures，flying and turning over through the air．
Skydiving is a method of leaving an airplane and returning to the earth with the help of gravity，then slowing down by using a parachute （降落伞）．It may include more or less free-fall，a time during which the parachute has not been used and the body gradually accelerates （加速） to the highest speed．
There are three choices for the beginners．However，before you try skydiving，a ground course on safety is required．The first method is accelerated free-fall．You jump out of the plane while being held by two coaches，one on either side．They hold onto you until you open your parachute．The second method is called static line．After jumping out，you will experience free-fall for a second or two．Then the weight of your body will pull the line tight，opening the parachute．
Tandem （串联） is the most popular because it is the easiest．You and the coach are
tied together，the coach behind，with you in front．You jump out of the plane together，and the coach takes care of opening the parachute．
For each of these three methods，the coaches give instructions in the air with hand
signals （信号） or a radio．If you are eager to try something challenging and would love to feel the freedom of flying，skydiving might be an adventure for you．Who knows？With risk and excitement mixed together，skydiving might just change your life．
61．Do thousands of people try skydiving each year？Yes．/Yes，they do．
62．How many choices are there for the beginners？3/Three．/There are three choices
63．Why is tandem the most popular？Becauseitistheeasiest．
64．How do the coaches give instructions in the air？With hand signals or a radio．
65．What is the passage mainly about？What skydiving is and how beginners skydive．/The introduction of skydiving and the methods for beginners．
