Record-breaking. Abnormal. Dangerous. That’s how the National Weather Service described the heat wave hitting much of North America.

The heat wave has already broken all-time high temperature records in places unaccustomed to such extreme heat. For example, Oregon’s capital city, Salem, recorded the highest temperature in its history on Sunday: 130F, breaking the old mark by 4 degrees. The temperature hit 104F in Seattle. It was an all-time record for the city better known for rain than heat and was the first time the area reached such a high temperature since records began being kept in 1894.

Weather forecasters said the heat wave was caused by an extended “heat dome”which allowed hot air from the Gulf of Mexico and the Atlantic to stream northward over much of North America.

This current heat wave was yet more evidence of the impact of human-caused climate change. “When it comes to record-breaking heat events, the study has been run for event after event in region after region in year after year. And the answer is almost always the same,” said Kristie Ebi, a professor at the University of Washington “The days-long heat wave is a taste of the future as climate change reshapes global weather patterns.”

“Another aspect that we see connected to climate change but that we don’t hear about as much is the fact that there is also a lot more water in the atmosphere now. As we warm the oceans and warm the air, there is more evaporation（蒸发）and that wetter air makes us feel hotter,” added weather forecaster, Jennifer Francis. “A combination of high temperature and moisture（湿度）in the air means dangerous conditions for the young, elderly or others who are not healthy. Please drink plenty of water; stay out of the sun and in air-conditioned rooms.”

【小题1】What was the previous temperature record in Salem?

A．104F.

B．126F.

C．130F.

D．134F.

【小题2】What is the root cause of the present heat wave in North America?

A．The climate change.	B．The northward air streams.
C．The extended "heat dome".	D．The moisture in the atmosphere.

【小题3】Which of the following is a suitable title for the text?

A．The Dangerous Heat Wave Will Last Long

B．A Heat Wave Roasts Much of North America

C．Measures Must Be Taken to Protect the Young and Elderly

D．The "Heat Dome" Is Expected to Cover the Pacific Northwest

【小题4】Where can the text be found?

A．In a first aid guidebook.	B．In a weather forecast.
C．In a news report.	D．In a professor's lecture.