“I sometimes get up at three or four in the morning and I surf the net.”
   “I often check my e-mail forty times a day.”
   “I often spend more than three hours during one time on the net.”
   “I spend more time in chatting rooms than with my 'real-life' friends.”
    Do you know any people like these? They are part of a new addiction(瘾) called Internet addiction. Internet addicts spend at least thirty to forty hours online every week. The use of the Internet can be an addiction like drug(毒品) use. People lose control of the time they spend on the Internet.
   For example, one college student was missing for several days. His friends were worried, and they called the police. The police found the student in the computer lab: he was surfing the net for several days straight.
   Studies show that about 6% to 10% of Internet users become addicted. And people worry about the teens because the Internet is changing the playing field for some of them. They spend more time in cyberspace than in the real world of friends and family. Is 'surfing the net' a hobby or an addiction for you? You may have a problem if you have these symptoms(症状):
    ●You do not go to important family activities or you do not do school work because you like to spend hours on the Internet.
    ●You can't wait for your next online time.
    ●You plan to spend a short time online, but then you spend several hours.
    ●You go out with your friends less and less.

有关太阳活动的叙述，正确的是（　　）

只含有碳、氢或碳、氢、氧的物质充分燃烧后的产物均为CO₂和H₂O。相同分子数目的下列物质分别充分燃烧，所消耗O₂的质量相等的是（   ）

①C₂H₅OH

②CH₃OH

③CH₄

④C₂H₄