She is not confident about her ability to run a 5k race.

她对自己跑5公里比赛的能力不自信。

同一单元的其他句子

• Regular exercise is essential for maintaining good physical fitness.规律锻炼对于保持良好身体健康至关重要。
• She joined the school basketball team to improve her teamwork skills.她加入学校篮球队以提高她的团队合作技能。
• Why don't you try yoga to reduce stress and increase flexibility?为什么不试试瑜伽来减轻压力并增加柔韧性呢？
• He doesn't like running because it makes him feel tired quickly.他不喜欢跑步，因为跑步使他很快感到疲惫。
• Make sure you warm up before starting any intense workout.在开始任何剧烈锻炼前，一定要热身。