Detailed Instructions: In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
Q: Article: Mo was waiting in the corridor outside her class. She was feeling sick. She had two exams that day and physics was first .She really hated physics. It was her worst subject. Terry Looked back at her from the front of the line, and then looked away quickly. Mo thought she looked guilty. She didn't have a problem with physics she didn't have a problem with anything ... _ ! "Hi, Mo, it's your favorite exam today, "said Nima, laughing as she joined the line .Terry was looking at Mo again. "So what's wrong with her?" asked Nima."I thought you were friends." "Yes, so did I," said Mo." But she hasn't spoken to me for two weeks now. She promised to help me review for the physics exam too, but then she's ignored all my calls and texts .And when I rang her house, her mum just told me she was busy. She's forgotten who her friends are!" said Mo angrily. "Are you listening to me?" Mr. Reed was talking to the class and the other students were going into the exam room. Mo gave Nima a worried look and followed them. Mo couldn't answer question number five. She looked up and saw Terry sitting two rows in front of her. Mo couldn't believe it! Terry was holding her phone on her knee under the table and reading from it. Is that how Terry always got such good grades? She felt really angry at Terry, but she didn't know what to do. She thought about telling the teacher, but what would everyone else think of her? "Stop writing and put your pens down" said Mr. Reed as he started to collect the exam papers. Oh no, Mo hadn't answered two of the questions. She was going to fail again! Mo wanted to talk to Terry at lunch time, but she couldn't find her anywhere. The next exam was history. That was Mo's favourite subject but she wasn't feeling good. Mo went to the library to study, but she couldn't concentrate. She didn't know what to do about Terry. She thought about telling a teacher, but everyone would hate her if she did that. "It wasn't fair!" she thought. "Terry was getting good grades by cheating all that time." thought Mo. Just then, Mr. Reed walked past her table. "Mr. Reed." Mo was sitting behind Terry again in the history exam that afternoon. Mo was feeling terrible. Why had she told Mr. Reed? But it was too late now. And anyway, Terry didn't want to be her friend! Mr. Reed wanted her to look at him and nod if she saw that Terry was cheating in the exam. She was working on the last question when she saw that Terry had her phone under the table. Without thinking, Mo looked up and nodded to Mr. Reed. Terry was too busy looking at her phone and she didn't hear him as he walked silently up to her table. Mr. Reed didn't say anything. He just picked up her exam paper, tore it in half and pointed to the door, to tell Terry to leave the room. Terry was crying as she walked to the door. Everyone was staring at her and Mo felt really guilty now. Why did she tell Mr. Reed? Mo was walking towards the school gate, when she heard footsteps behind her. It was Terry. "Mo, please wait! I want to talk to you." Mo could see that Terry had been crying, her face was pale and her eyes were red. Mo couldn't say a word. "Listen," said Terry. "I'm really sorry I haven't answered any of your calls, but we're having a terrible time at home. My dad had a heart attack two weeks ago and he's in hospital. He had a big heart operation today and I was very worried about him. I know it was stupid, but I was reading texts from my mum to see how the operation was going, but Mr. Reed caught me with my phone. He thought I was cheating. He believes me now, but I have to take the exam again. I'm sorry I didn't tell you what was happening. I haven't forgotten that you're a good friend'. Will you forgive me? "
Answer: she was worried that she would fail the physics exam
A:
At the beginning of the story Mo felt sick most probably because _ .