题目内容：

    The school year has barely started in Denver, and French teacher Tiffany Choi is already worried that her students are suffering from absent-mindedness. The problem isn’t texting, playing video games or passing notes. It’s Denver’s ongoing heat wave.

“Today was a little bit hot, so I noticed kids were very sleepy and they were having to get up to drink water quite often.” said Choi, who works at Denver’s East High School. “If you lose too much water, and you have to keep going to the water fountain, that can take away from their classroom experience.” While nodding off in class on a warm day may seem like a right of passage for the average teen, Choi’s observation carries a bigger consequence than parched (干燥的) lips.

“There’s been quite a few media reports about teachers noticing that students weren’t able to focus on hotter days,” said R Jisung Park, a researcher, “Does a hotter climate during the school year actually affect the rate of learning?” The drops in academic achievement couldn’t be explained by hotter weekends or hotter summers, but the trend was connected to higher temperatures on school days alone.

The connection between lost learning and a greater number of hot days is one more example of how climate change is already affecting our lives-and it’s an alarm bell for what we stand to lose in the future. Humans still have time to lessen the worst consequences of continued global warming. But unless significant changes occur in the next decade-which seem more and more unlikely—the world will be locked into an inescapable period of heat waves unlike our species has ever seen.

1.What may cause students absent-minded according to the text?

A.Video games. B.Text messages.

C.Heat waves. D.Classroom notes.

2.What can be inferred from the second paragraph?

A.Lacking water is vital for kids being sleepy.

B.Extreme heat may lower a kid’s ability to learn.

C.Nodding off in class is a sign of respecting teachers.

D.Kids are more interested in drinking water than sleeping.

3.How does the author feel about dealing with the future global warming?

A.Optimistic. B.Uncertain.

C.Worried. D.Firm.

4.What is the best title for the text?

A.The hotter it grows, the less kids are learning.

B.The consequences of continued global warming.

C.The reasons why kids are absent-minded in class.

D.The hotter it grows, the more focused kids become.