英语阅读强化训练
Keep your eyes on the sky ― it looks like 200x will be a big year for tornadoes. As of the first week in April, there have already been 445 “twisters” in the United States. Last year, there were only 96 tornadoes by the beginning of April. According to the National Oceanic and Atmospheric Administration (NOAA), a government agency that studies the environment, this marks the most intense tornado activity in the first three months of any year since 199x. Previous years with a busy start have produced high numbers of tornadoes throughout the year.
For those living in “Tornado Alley” from west Texas all the way up to North Dakota, springtime is tornado time. What exactly causes a “twister”? Tornadoes form when moist, warm air is caught under dry, cool air. When the warm air rises, it upsets the cool air, spinning (使快速旋转) the air into a funnel-like shape. The spinning air is officially categorized as a tornado once it touches the ground. These twisters can reach extremely high speeds, sometimes more than 250 miles per hour!
Scientists try to measure the speed and damage of tornadoes using what is called the Fujita Scale, or F-scale. The scale ranges from F0, with winds under 73 mph, to F5, with winds between 261 and 318 mph. Violent tornadoes in the F4 and F5 categories sometimes last more than an hour, and cause incredible amounts of damage, often destroying everything for hundreds of miles. Fortunately, these account for less than 1 percent of all tornadoes.
【英语阅读强化训练】相关文章：
高考英语阅读理解的强化训练01-10
中考英语阅读理解强化训练08-13
高考英语冲刺复习：阅读强化训练07-14
MPA考试英语阅读理解强化训练01-11
MPA考试英语阅读理解强化训练试题01-11
初中英语阅读理解强化训练09-22
初中英语阅读理解强化训练及答案09-05
英语六级阅读强化训练题答案讲解09-11
2016年公共英语考试四级阅读强化训练题10-17