What a cold winter! But Melissa and Lydia still got up early, just to find a seat in the classrooms. Every winter the classrooms are always full of people. It"s time for students to prepare for the entrance tests for graduate studies. They were still quite sleepy. Maybe Melissa knew where they were heading. Lydia just followed Melissa, her eyes almost closed.

Arriving a bit later then other students, they found that classrooms were quite crowded. So they climbed to the upper floors, one after the other. Finally, they arrived at the highest floor. Melissa checked one classroom after another but they could not find two free seats anywhere. They walked along the passage, and at last Melissa was standing in front of a silvery white door. It was strange in deed, as doors in this old teaching building were normally red, deep red, but as Melissa just wanted to sit down and open her books, she did not notice.  (来源：专业英语学习网站 http://www.EnglishCN.com)

Ah, I hope there are some empty seats here. Melissa read the sign, Room 530, and then entered it. Lydia just followed her into the classroom.

"It"s empty"!

Lydia opened her eyes wide and could not believe what she saw. How could it be? She was thankful nevertheless. Melissa was so relieved that she noticed nothing out of the ordinary, not even the silvery white desks and chairs which like the doors were normally deep red. The blackboard was dark green, which was quite unusual for old buildings. She just chose a seat and sat down as did Lydia. She was still sleepy and forced herself to fetch her books from her school bags. But something suddenly came to her mind and a light of coldness overwhelmed her. She was astonished and awake all at once and looked around the classroom.

"Where are we"? She screamed suddenly.
"What"? Melissa said, drowning herself in her books. "Where are we"? Lydia repeated. Melissa was awoken from her drowsiness by Lydia"s sudden outburst.

Lydia was sure that even in their new teaching buildings there were no classrooms like this. 
"Hey, we are in room 530 of the North Teaching Building", said Melissa.

"530! But there is no room 530 in the North Teaching Building! Can"t you see anything odd here"?

Lydia was scared now. "What...what do you mean"?

Melissa looked attentively at the classroom for the first time. "Er, it"s really somewhat different from the other classrooms, but I"m sure it"s marked room 530".

"No 530 is in the North teaching building. Have you forgotten that the left side of the 5th floor of the North building is normally left empty? There are just 15 classrooms on that floor. How could there be a room 530"?

The silvery white color seemed to be vaporized and things were a bit vague in the room. "Well, I don"t understand. I just saw this room and entered it. Maybe, maybe we should leave it, now", Melissa said with a quiet, hesitant tone.

They stood up to leave. It seemed that nothing was real. To Lydia and Melissa"s open-mouthed horror and shock, the desks were moving!   "Oh my God" cried Lydia as she tried to walk to the door. 

"Where are you? I can"t see you", Melissa cried!
Lydia could not see Melissa either. The door, had vanished! There seemed to be a thick fog around her. Frightened she walked back. Then she saw Melissa.

                         To be continued.