题型：问答题 下列有关筛选化学致癌物的短期致突变试验的描述中错误的是（）A.需选择一组致突变试验B.在组合试验中有一项是阳性结果，即可认为该受试物为致突变物C.组合试验中阳性结果愈多，受试物致癌的可能性就愈大D.可检出遗传毒性致癌物E.可检出遗传毒性非致癌物 查看答案
题型：问答题 阅读理解。 阅读下面短文，根据所读内容在表格中的空白处填入适当单词。注意：每个空格只填一个单词。 Nowadays more and more people are concerned about their health, but how to keep healthy? Different people may give different answers to this question. In my opinion, it is essential to do the following. First, it is absolutely necessary to take some exercise at regular time every day. Research shows that getting plenty of exercise can make the heart beat faster and the lungs work harder. This strengthens the heart, reduces the chance of heart attack, and helps lower blood pressure. That's why more and more people are becoming active in various kinds of sports and exercise. Every morning many people get up early and take much exercise. Some play ball games while others run, jog, walk or dance to music. In the afternoon, there are also many people keen on sports. Through sports and exercise, people become healthier and stronger. Medical researchers have proved that what people eat affects their health. They advise people toeat more fruit and vegetables and less meat such as beef and pork because meat contains more fat than poultry (家禽) and fish. Fat can build up in the arteries (动脉), block the flow of blood, and cause a heart attack or stroke (中风). Getting rid of bad habits like smoking and drinking alcohol is also an important way to keep healthy. Smoking and drinking alcohol injure one's health a great deal, and therefore should begiven up. Unfortunately few people follow this advice.Best title: How to keep 1._____TipsDetailsTake some exercise 2.____ Benefits of plenty of exercise:The heart can be 3._____ ;The chanceof heart attack can be 4._____ ;Blood pressure can be 5._____ .Pay attention to your6._____ 7.____ Suggestions:Fat can result in a heart attack or stroke; More fat may be 8._____ in meat. To eat more fruit and vegetables; To eat less meat such as beef and pork.Give up bad habitsHarm of bad habits: smoking and drinking alcohol do 9.____ to one's health.Advice: Getting rid of bad habits like smoking and drinking.10._____If people follow these ways, they will greatly improve their health. 查看答案