单项选择题 How to Determine a Topic for Research Because you are going to put a lot of your time and energy into your research project(项目),the topic is especially important. In many instances your instructor may give a specific(特殊的)topic. If this is done, you have little choice, but most instructors will permit or even welcome a slightly changed focus(中心)in a topic if it is supported by good thinking. In some of your classes, the instructor may present a suggested list of several topics from which you are to make a choice. If this is done, do not simply select the first idea that attracts your attention. It may be one with which you will soon become bored, or it may be one on which you would have difficulty finding all the necessary information. Looking at the topics, try to consider how you might go about developing each of them. When you find out what seems especially interesting and worthwhile(值得骄傲的),do a bit checking in the library to see if you can get the basic resources you will need. Choosing a good research topic does not necessarily mean finding something that has a lot written about it. Many times you will have to research around a topic in order to find out the most useful information. Exciting and original topics often come to mind by combining two completely different interests. Let us say that you are interested in child psychology(心理学的)and in sports. Perhaps you can combine these into a study of the effect that is watching(可得到的)on the subject, you can research the topic individually and, by putting your information together, then draw a conclusion.Choosing a topic for research is important in that you will put a great deal of time and energy into it.A．RightB．WrongC．Not mentioned

单项选择题 在家庭生命周期各阶段中，收入以薪水为主，支出随子女诞生后而增加的时期是（）。

单项选择题 Natural Medicines Since earliest days, humans have used some kinds of medicines. We know this because humans have survived. Ancient treatments for injury and disease were successful enough to keep humans from dying out completely. They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment. Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals. Yet injuries are treated. And diseases are often cured. How? By ancient methods. By medicines that might seem mysterious, even magical(有魔力的). Traditional medicines are neither mysterious nor magical, however. Through the centuries, tribal (部族的)medicine men experimented with plants. They found many useful chemicals in the plants. And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases. Experts say almost 80% of the people in the world use plants for health care. These natural medicines are used not just because people have no other form. of treatment. They are used because people trust them. In developed areas, few people think about the source of the medicines they buy in a store. Yet many widely-used medicines are from ancient sources, especially plants. Some experts say more than 25% of modern medicines come, in one way or another, from nature. Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive. So scientists' interest in traditional medicine is not new. But it has become an urgent concern. This is because the earth's supply of natural medicines may be dropping rapidly.The passage indicates that ancient treatments for injury and disease were ______.A．much more successful than modern onesB．successful enough for humans to surviveC．successful in all casesD．of little help to humans