Hello, Greg, I'm going to take your second question. So, about the sales and marketing expense per enrollment decreased in this quarter. So, firstly, let's recap what happened in the first quarter in 2020. So, in the first quarter, as we mentioned on our Q1 earnings call, majority of the enrollments are coming from the first-time users. And for the first time users, like we usually need to pay attention and spend more energy to convert them to sign up for our paid course enrollments. So, then in the first quarter, if we divided the sales and marketing expenses by the paid enrollments, we basically had a customer acquisition cost around RMB 970. And in the second quarter, usually, the second quarter is one of the largest retention season in the year. So, especially in April and in May, students in the spring semester, they will be signing up for the next semester in summer. So, that's why we have a proportion of gross billings and enrollments actually come from the existing students. And that's why we always say, for K-12 education, it is an industry that could accumulate loyalty and long-term customers. So, for our existing students, basically, the customer acquisition cost is zero. And the cross-selling, retention and word of mouth referrals are the key to our continued customer acquisition cost. So, then the key is to provide the best service to the students and to achieve the most excellent cross-selling, retention and word-of-mouth referral. Only leverage list that can contribute to our long-term success, and because like we have this part of the enrollments coming from the existing students that actually further lowered the weighted average customer acquisition cost in our second quarter. And if we look at the seasonality across the year, the first quarter and the third quarter will be a quarter that majority of the students are the first-time users. And for the second quarter and the fourth quarter are the biggest retention seasons. So, we will see the customer acquisition cost in the second quarter and in the fourth quarter to be significantly lower. Especially for this year, we do foresee the weighted average customer acquisition cost to be further lower in the fourth quarter this year. So, I hope this address your question. Thanks.