9.解析：用反身代词，说明flaw是在youngsters中的。

答案：themselves

8.解析：修饰affect，所以用副词。

答案：greatly

7.解析：skills是被用的，所以用被动语态。

答案：be used

6.解析：修饰名词用形容词。

答案：valuable

5.解析：介词后面用v.­ing。

答案：learning

4.解析：这是定语从句。

答案：that/which

3.解析：be described as被描述成、被认为。

答案：as

2.解析：excessive是元音开头，所以用an。

答案：an

Sport not only is physically challenging，but it can also be mentally challenging.Criticism (批评) from coaches，parents，and 　1　 teammates，as well as pressure to win can create 　2　 excessive (过度的) amount of anxiety or stress for young athletes (运动员).Stress can be physical，emotional，or psychological (心理的)，and it can lead to burnout.Burnout has been described 　3　 dropping or quitting of an activity 　4　 was at one time enjoyable.

The early years of development are critical years for 　5　 (learn) about oneself.The sport setting is one where 　6　(value) experiences can take place.Young athletes can，for example，learn how to work together with others，make friends，and gain other social skills that will 　7　 (use) throughout their lives.Coaches and parents should be aware，at all times，that their feedback to youngsters can 　8　 (great) affect their children.Youngsters may take their parents' and coaches' criticisms to heart and find a flaw (缺陷) in 　9　.

Coaches and parents should also be careful that youth sport participation (参与) doesn't become the work for children.The result of the game should be 　10　 important than the process of learning the sport and other life lessons.

1.解析：其他的。

答案：other