Chinese smartphone makers are increasing budgets to unveil new p

Chinese smartphone makers are increasing budgets to unveil new products to coincide with the peak sales season that starts in the July-August summer vacation and extends through the third quarter of every year. The summer vacation is a prime time for smartphone sales as many students may want to upgrade their phones. Smartphone companies are keen to pounce on the time window to grow their businesses.
The best season for s______ smartphones.
【正确答案】：selling