C．Failing to register ahead of time.

　　D．Loss of Magnus Health account.

　　答案与解析：A　考查细节理解。根据倒数第二段中的"Health forms must be completed... if not, summer school classes and activities may not be accessible to your kid"可知，如果健康表格没有及时完成并提交，可能导致学生不能参与暑期班课程和活动。

　　B

　　[2019·成都第一次诊断]For the brave in the armed forces, being sent away from home for months at a time is just part of the duty. However, it's never an easy one to perform especially for those with children. So when I found out I was going to be stationed in South Korea for a year, I was nervous about how my five children, particularly my eldest daughter Abigail, would take the news since it meant I wouldn't be home to see her graduate from high school.

　　Incredibly, Abigail told me not to worry and even suggested we live_stream the event among family members when I leaked the news. "We've been lucky you haven't had to be sent abroad yet. Anyway we can get connected through the Internet. See me on your phone on my spot，" Abigail said. She stepped into many of my roles when I was gone. I wanted to find a way to thank her and show her how proud I was of her. I started planning the special surprise when my request to return home a few weeks early to attend Abigail's graduation ceremony was approved.

　　When my time in South Korea finally came to an end, I flew home, rented a car, and stayed in a hotel. And on Abigail's graduation day, I hid in an office behind the stage waiting until I heard my daughter's name called. I just kept thinking "Don't cry. Don't trip in your heels. Don't fall over." At last! Abigail was up on stage. I slipped up behind her, whispered in her ear, and around she turned! "I was just thinking, like, 'You aren't supposed to be here. What? What? How？' It was the biggest shock... I'm pretty sure my dad made people he didn't even know cry. Emotional for everyone，" Abigail cried.

　　You know what followed: Embraces, kisses, tears, laughs, flowers, wishes... Aren't they what a family has in store?

【语篇解读】　本文是一篇记叙文。"我"将被派驻韩国一年，因此，大女儿Abigail的高中毕业典礼"我"将无法参加，但是为了给她惊喜，在她的毕业典礼上，"我"出现在了她面前。本文体现了学科