Because of the epidemic, we have been taking online classes for more than a year. For those working hard in the science park, the flexibility of online classes allows them to better grasp the time slot for continuous learning. Some one uses the time waiting for his child to attend classes in the Costco parking lot. Some one is sometimes too tired after get off work and afraid of falling asleep in class. The other one always have his children to supervise them during class. In any case, meeting on the Internet at a fixed time has become a ritual. Learning requires continuous accumulation, and in today's listening practice, I found that everyone has become so good, which is really gratifying. I am very happy to be your teacher and go so far with you all. I am very fortunate to be able to join such a joyful learning time with you all.