题目内容：

    As the school year barely starts in Denver, French teacher Melanie is filled with worry that her students are always absent-minded. Yet, the problem isn’t messaging, enjoying video games or delivering notes. Surprisingly, the problem is about the ongoing heat wave in Denver.

“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 Melanie, 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 acceptable for the average teen, Melanie’s observation carries a bigger consequence than dry lips.

“There have 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. Without the unlikely important changes in the next 10 years, the globe will be trapped in an unavoidable era of heat waves that were unprecedented (前所未有的) for human beings.

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.Kids often go to the water fountain for lack of water.

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.Indifferent.

4.What does the text mainly talk about?

A.The way that global warming continues.

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

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

D.The hotter it grows, the harder it will be for kids to learn.