Lecture Hall, University of Hong Kong.

Dr. Wright, an American, is giving a lecture on his genetic information course.

The podium was crowded with students from all over the world, who were attentive and listening with relish.

The door at the exit of the podium was hidden in the lecture hall, and Xie Jun's hesitant and bewildered face was revealed in the crack of the door.

Xie Jun knew her tutor's habits, so she didn't mean to disturb the tutor's class, but stood quietly behind the door.

She knew that when Dr. White was in class, even if the sky fell, it would not affect the instructor's concentration. Moreover, his only emotion towards anyone who interrupted his class was anger.

The hall reverberated with Dr. White's distinctive, slow-paced Texan accent, for which Texans are known for their accent and the rhythm of their lives. Of course, there are also people who complain about their too peaceful lifestyle.

Everything was so familiar and intimate, Xie Jun felt as if he had returned to the days when he was studying diligently.

At this point, Dr. White was talking about the use of DNA as a modern storage medium.

"Can anyone take the initiative to tell me how many books you have stored in your personal bookcase?"

Dr. Wright's classes have always been lively, and the students' enthusiasm for answering questions is very enthusiastic.

"I have more than 100 books, but I almost never finish them"

"It's only a few dozen."

"God, it's going to take me a few years to see them!"

"If you count it as a family unit, I should have thousands of books in my study"

The crowd let out a "Wow! Obviously, this classmate who answered the question must have a good family background.

"OK, it seems that the students in this class have a much higher chance of becoming poor professors than rock musicians."

The cheerful laughter in class echoed Dr. White's humor. His rigorous and humorous teaching style is obviously one of the reasons why he is popular with his classmates.

"A novel is about 1MB bytes. So, who can tell me about the largest Library of Congress in the United States? “

The whole class was silent for a short time.

"10 million copies!" A handsome boy from France replied.

"I just found it on my phone," he playfully winked at the girls next to him, his wit eliciting a burst of laughter.

"MR. SMART SIR, PLEASE CONTINUE TO CONVERT, HOW MANY BYTES IS THAT?"

"About 10 terabytes" This handsome young man not only seems to have excellent appearance, but also has a very fast reaction speed.

"Mr. Mike, that's totally correct, I'll give you an A+ in the grade assessment" Dr. White winked mischievously at Mike as well.

The atmosphere in the classroom is more relaxed and enjoyable.

"With such a visual comparison, I would like to tell you that the DNA molecule is an even more incredibly dense storage medium"

"The amount that 1 gram of DNA can store is about 2 petabytes,"

"That's 200 times the number of books in the Library of Congress!"

There was a lot of commotion in the classroom again.