In November 2017, we followed it up with“e-Conomy SEA Spotlight 2017-Unprecedented growth for Southeast Asia's $50B （ 71 ）”There, we highlighted some of the most significant industry trends, such as the boom of e-commerce marketplaces and ride hailing services as well as the acceleration of （ 72 ） in the region. We also discussed the encouraging progress made by ecosystem players in addressing challenges that constrain the internet economy from reaching its full potential, such as the availability of homegrown tech talent, digital payment solutions, last-mile （ 73 ）, high-speed internet access, and consumer trust.
Coping with the continuous development of Southeast Asia's internet economy ecosystem, “e-Conomy SEA 2018-Southeast Asia's internet economy hits an inflection point”includes sectors of the internet economy not covered in our previous research, such as Online Vacation Rentals （ 74 ）, Subscription Music&Video on Demand （ 75 ）, and Online Food Delivery（Ride Hailing）. These sectors have achieved substantial adoption among Southeast Asian users, resulting in significant business size and growth.
74（74）
设16位浮点数，其中阶符1位、阶码值6位、数符1位、尾数8位。若阶码用移码表示，尾数用补码表示，则该浮点数所能表示的数值范围是（ ）。
平均故障间隔时间MTBF用以表示系统平均无故障可正常运行的时间，下列与MTBF有关的叙述不正确的是______。
