题目

J、L、M、R、T是原子序数依次增大的短周期主族元素，J、R在周期表中的相对位置如下表；J元素最低负化合价的绝对值与其原子最外层电子数相等；M是地壳中含量最多的元素。（1）元素T在周期表中位于第_________族。（2）J和氢组成的化合物A每个分子由4个原子组成，其结构简式为________________，已知充分燃烧a gA物质时生成1mol二氧化碳气体和液态水，并放出热量b kJ，则A物质燃烧热的热化学方程式是_______________________________。（3）M和R形成的一种化合物能All of us eat every day, but most of us don’t understand nutrition(营养). How much do you know about good nutrition? Are the following statements true or false?1. People who don’t eat meat can stay healthy.True. As long as people eat enough milk, eggs and meat alternates(替代物), they can get enough protein.2. Fresh vegetables cooked at home are always more nutritious than canned vegetables.False. The difference depends more on how vegetables are prepared than whether they are fresh or canned. Vegetables cooked in too much water can lose a large quantity of vitamins.3. Food eaten between meals can be just as good for health as food eaten at regular meals.True. Nutritional value depends on what types of food you eat, not when you eat them. Eating an egg or an orange between meals can contribute to a good diet.4. Taking extra vitamins beyond the recommended daily allowances won’t give you more energy.True. It’s widely believed that extra vitamins provide more energy. But taking more than the baby needs doesn’t make it function better, just as overfilling your gas tank doesn’t make your car run better.5. Natural vitamins are better supplements(补充)for the diet than synthetic vitamins.False. There is no difference. A vitamin has the same properties(性质)and specific chemical structure whether made in a laboratory or taken from plant or animal parts.6. Older people need the same amount of vitamins as younger people.True. Older people need the same quantity of vitamins as younger people although they need fewer calories. Certain illnesses raise the requirements for some vitamins, but that is true for the young as well as the old.7. Food grown in poor soil is lower in vitamins than food grown in rich sold.False. The vitamins in our foods are made by the plants themselves. They don’t come from the soil.However, the minerals in a plant depend on the minerals in the soil.If you have answered these questions correctly, you can say you know much about food and nutrition by today’s standards. But remember that nutrition is a growing science and that may be aged as new information is obtained.【小题1】The main purpose of the passage is to           .A．list today’s standards of some food and nutritionB．introduce what should be eaten and what notC．explain what is helpful to your health and what is notD．test our nutrition IQ by judging the problems listed【小题2】From the surrounding words and sentences we know that the underlined phrase “contribute to” means         .A．help to bring aboutB．take the place of C．make room forD．turn to【小题3】The underlined word “synthetic” most probably means       in Chinese.A．不同的B．特别的C．合成的D．天然的