阅读理解专项练习50-30CMSG(monosodium glutamate) is a food additive(食品添加剂),which has been widely used by many food factories all over the world since it appeared first in Japan in 1909. MSG is a substance that is added to some food to improve its original(原先的) taste and colour. It is used in foods around the world such as cakes, bread, frozen meats, fish and vegetables. In the beginning, people thought MSG was safe just like salt and sugar. However, in 1968 some people reported they seemed to have bad reactions(反应) to MSG after having had a meal at a restaurant. They included headaches and quick heartbeat(心跳).It was also reported that MSG excited a persons brain and caused his death in Japan. Scientists think that MSG may lead to many neurological disorders(神经紊乱).In mice studies done by a university, the evidence showed the mice didnt want to eat the food including MSG. Today many food companies “hide” MSG on food labels(标签) by using different names. If you see “natural flavorings”,“hydrolyzed protein”and “spices” in a food label, you are probably seeing a hidden way to “report” MSG in a food label. Every time we have a meal in a restaurant, we always feel the food very delicious to taste, but sometimes it is dangerous for our health because some poisonous food additives have been added to the food. To protect peoples health, our governments, from central to local, are taking actions to stop factories producing poisonous food additives.41. Monosodium Glutamate is _ A. a food B. an additive C. a factory D. a country42. MSG is often used in _. A. frozen meats B. cups C. clothes D. book covers43. The examples in the second paragraph tell us _.A. the food including MSG is delicious B. people like to eat in a restaurant C. mice like eating the food including MSG D.MSG is not safe sometimes44.If you see “natural flavorings”,“hydrolyzed protein” and “spices” in a food label, you will know _. A. you must eat the food in a hidden way B. the food label must be hidden C.MSG is probably added to the food D. you must report the food to your parents45.The underlined word “substance” in the article means _. A. colour B. material C. taste D. food【主旨大意】本文介绍了味精的优点和害处。41. B 从短文第一句“MSG(monosodium glutamate) is a food additive”得出答案。42. A从这句话“It is used in foods around the world such as cakes, bread, frozen meats, fish and vegetables.”得出答案。43. D从此句“Scientists think that MSG may lead to many neurological disorders(神经紊乱).”得出答案。44. C从这一句“If you see “natural flavorings”, “hydrolyzed protein” and “spices” in a food label, you are probably seeing a hidden way to “report” MSG in a food label.”得出答案。45. B 根据句意，得知意为“物质”。A If you are cycling in foreign countries, you will need to know what these traffic signsand signals mean.1A sign like this one means that there is a bike lane(车道). If there is such a sign，you are required to use the bike lane.If there is not such a sign, you should ride with traffic as far to the right side of the road as possible.2This signal means you can cross the street along with pedestrians(行人). It has a green picture of a oerson walking instead of using the word“walk”.3This signal is the “dont walk”sign. It is a picture of a red hand, meaning you should stop. You should wait to cross the street until the green picture of the person walking is showing.4Car drivers and bikers must come to a complete stop at“STOP” signs.5A“YIELD”sign means to slow down and be ready to stop.If there are pedestrians or vehicles in or near the crossroad, you must stop. If there is no traffic in or near the crossroad and it is safe, you may go through.6This signal means you are coming to a zebra crossing. Car driversand bikers must stop to allow people in the zebra crossing to cross the street.7When people are working on the roads, parts of the road are oftendug up or rough(不平整的). Be careful when yon are cycling. Rough roads could make you fall off your bike.If you must move into the road to go around a work area，you should stop and look carefully to be sure there is no traffic coming.8A detour is a way of getting around a roadway that is closed. Roads are usually closed because of road work or dangerous conditions. If you must take a detour, be careful about the roads you arent used to.21What are cyclists required to do when they see the sign ? A.To ride against traffic.B.To ride on the left side of the road.C.To ride on the bike lane.D.To ride on the right side of the road22Which of the following signs has the same meaning as the sign ?23What should cyclists do when they see the sign ?A.They should be careful when they cycle on the rough road.B.They should take the rough road and fall off thei