下列属于腔肠动物和扁形动物共同特征的是（　　）

①将素材库中的两个视频文件拖进故事板

②启动会声会影软件并新建一个项目

③创建视频文件，保存为MPEG格式

④选择效果"百叶窗"，将效果拖入到两个视频中间

⑤切换到"效果步骤"

正确的操作顺序是（   ）

    A study of sleep in sparrows suggests the relationship between sleep and the ability to learn may be more complicated (复杂) than realized．

    Niels C. Rattenborg of the University of Wisconsin—Madison wanted to find out how the sparrows were able to deal with getting so much less sleep．He and his team brought eight wild birds into a lab and watched them for one year．They invented a game to check how well the birds could learn．In the game, the sparrows had to peck (啄) three buttons (按钮) in a certain order to get a food treat．The scientists discovered that the birds' ability to learn the right button order depended on (依靠) two things, the time of year and the

amount of sleep the birds had．

    During the migration (迁徙) season, the sparrows were restless at night and got much less sleep than usual．Even so, they were able to understand how to get the food quickly as if they'd had a regular night of sleep．Outside the migration season, they found the sparrows that got less sleep than usual had much more difficulty learning how to get the food treats than birds that had a regular sleep．

    The results show that the sparrows can deal with much less sleep during the migration season than usual．If scientists can find out why, they may learn from sparrows and find ways of helping people deal with getting much less sleep．Until scientists fully understand the relationship between sleep and learning, it's better to get plenty of sleep when preparing for an exam．

    What's the biggest online shopping day in the world? Not Valentine's Day. Not Cyber Monday or Black Friday. The winner is China's Singles' Day, celebrated on November11, or 11.11.

    Singles' Day began as a day for unmarried or uncoupled people to celebrate their lives. Single students, looking for an excuse to buy themselves presents, started it on November11,1993, reported The Guardian. It is symbolized by the four mumber ones in the date of November11 and is also called Double Eleven, in reference to the day it was started, said the BBC. It became a major shopping day in 2009. The CEO of an online shopping site --Alibaba-- tried to increase sales at the e-commerce company. The CEO, Daniel Zhang, launched an annual online sale on that day, said Fortune. When it first began, "Sigles' Day was very much an offline comfort to actual single people," noted the website atlas Obscura."A small group of students at Nanjing University are said to have chosen 11.11 as a day that singles could do activities like karaoke together." It quickly became a cultural phenomenon.

    Last year, Alibaba sold more than $1 billion worth of products in the first three minutes of the sales, reported Bloomberg News. Total sales on Singles' Day soared to $9 billion within 24 hours. That's four times bigger than Cyber Monday in the U.S., which is the Monday after Thanksgiving and traditionally a big shopping day. By comparison, online sales in the U.S. last year on Black Friday were just $1.5 billion, reported TechCrunch.

    Today, Singles' Day is very successful. Analysts say that this year, sales on China's Singles' Day will increase to a new high. In the U.S., Jennifer Wang, a co-founder of a company targeting Chinese-Americans, said, "We expect to have 3 million people coming to click Dealmoon for the Singles' Day launch." Some observers think Singles' Day could catch on globally.