能正确表示热力环流形成过程的选项是：
①近地面空气受热或冷却②同一水平面上产生气压差异③形成大气的水平运动④气流的上升或下沉运动
答案：D
题目分析：热力环流的根本原因是地面的 冷热不均，由于地面的冷热不均而引起空气是垂直运动；由于空气上升，则近地面形成低压，高空形成高压；空气下沉则近地面形成高压，高空形成低压，从而出现同一水平面上的气压差异，由于同一水平面上的气压差异而引起空气的水平运动。进而完成热力环流的形成。
点评：本题难度低，学生只要结合地面的冷热不均进而判断引起的热力环流的形成过程。可结合画图分析。
| 任务型读写。 阅读下面短文，根据所读内容在表格中的空白处填入恰当的单词。 注意：每个空格只填一个单词。 | ||||||||
| One reason Americans eat so many calories is that we tend to eat large portions (分量). Studies find that hamburgers and fries are generally offered in serving sizes two to five times larger than the appropriate meal size. Researchers find we usually clean our plates no matter how high they're piled, even if we already feel satisfied. See the suggestions below to further master the fine art of sizing up 估量) your snacks and suppers. Extremely large portions are one possible reason Americans continue getting fatter even as the percentage of our total calories from fat has gone down in recent years. Fortunately, portions are relatively simple to control because it's easier to count cookies than calories or grams of fat. Pre-picture portions. Use familiar objects to picture how much you should eat of a food before you pick up your fork or spoon. For example, a half cup of low-fat granola is about the size of your fist. A half cup of low-fat ice cream equals half an orange. Use a smaller dish. This tip might sound ridiculous, but it works. First and mostobvious is that you can't put as much food on, say, a salad plate. But psychologically, you're just not as prone to eat as heartily and quickly if your plate will be empty in 45 seconds. Have raw vegetables at every meal. Raw cucumbers, tomatoes, carrots, and peppers have few calories and lots of nutrients. A plate of them in the middle of the table almost always gets eaten up, cutting down appetite for the more calorie-dense meat. Start your meal with soup. Studies show that a bowl of soup at the start of the meal reduces overall meal consumption, since they are lowest in calories and highest in nutrients. Manage your fork. After every bite of food, put your fork down. Don't pick it up until you have thoroughly chewed and swallowed the previous bite. The goal is both to slow down your eating and to eat less. Remember: Your body needs 20 minutes of digestion before it sends signals to your brain that you are no longer hungry. | ||||||||
| ||||||||