Unit 2 The universal language Period 2 习题 3

Unit 2 The universal language Period 2 课件课件 3 基础落实基础落实 翻译句子翻译句子 1 Is he coming back today I guess so I hope not 2 They did nothing but sit there 3 All we can do now is wait 4 He gave the same answer before 5 I ll lend you one if necessary 单项填空单项填空 1 The school rules state that no child shall be allowed out of the school during the day unless by an adult A accompanied B being accompanied C to be accompanied D is accompanied 2 A bicycle by electric power which does good to the environment becomes quite popular in our city A driven B being driven C to be driven D is driven 3 In cold weather they can t choose but and sleep A lie down B to lie down C lying down D lay down 4 When what his name was he made no answer A asking B asked C ask D to be asked 5 Have you found the key to the door I wish I A have B do C did D had 6 you come earlier you could have met him A Should B Would C Could D Had 7 I ll be away on a business trip Would you mind looking after my cat Not at all A I have no time B I d rather not C I d like it D I d be happy to 8 You ought to have made an apology to Tom yesterday evening Yes I know I A ought to have B have to C should D must have 9 He is rather difficult to make friends with but his friendship is more true than any other A once gained B when to gain C after gaining D while gaining 10 Although she believed that she had a good chance of recovering the doctor said that few could come back to normal after getting this disease A if any B if so C if not D if ever 11 Will you waste your time and money on that Certainly A I not B don t C not D no 12 Will you go home tomorrow morning No I am going to a lecture or at least I am planning A on B to C so D it 13 Are you a teacher No but I A used to B was used to C used to be D used to do 14 I listen to English every day over the radio interesting A Sounds B Sounding C It is sounded D Sound 15 What s Tom doing in his bedroom his sports shoes A He looks for B He looking for C To look for D Looking for 能力提升能力提升 任务型读写任务型读写 Have you ever wondered why there are so many skin colors in the world Do you know why people living in particular areas usually have a certain color Biology and history are the two reasons for this Skin contains something called melanin which determines a person s skin color The more melanin a person has the darker his or her skin will be The amount of and the production of melanin are controlled by genetics but can be affected by other things such as sunlight If a person lives in a place with less sunlight a person s body will produce less melanin making the skin lighter Skin color is also affected by another source vitamin D Humans all need vitamin D to build bones People can get it by eating foods such as fish and milk or from sunlight so sunlight absorbed by melanin cannot be used for vitamin D production Therefore a dark skinned person will produce less vitamin D than a light skinned person when they received the same amount of sunlight The connection between vitamin D production and skin color is clear when we look at evolution The earliest humans lived in Africa and their dark skin covered with hair When they moved to places that had less sunlight their bodies produced less vitamin D because of their dark skin As a result their skin made less melanin so they could get enough sunlight to produce vitamin D Their skin gradually got lighter and they lost hair Now people living in areas with strong sunlight like Africa have darker skin while people living in other areas have lighter skin The exception to this is the Inuit who live in a place with little sunlight but have dark skin because they eat a lot of fish and have enough vitamin D Evolution has given us a rainbow of skin colors Humans have always had melanin to determine our skin color What has changed through history is the environment where we have lived This has in turn changed our melanin production and eventually skin color Brief 1 People living in a particular 2 usually have the same skin color and there are many different skin colors in the world Reasons for skin color The reasons for different skin colors mainly 3 in biology and history Biology reasons The amount of melanin by which a person s skin color is 4 varies from people to people The more melanin a person has the 5 his or her skin will be Vitamin D is another source 6 skin color Vitamin D is necessary for humans to build bones Sunlight contributes to vitamin D in the skin History reasons The earliest people in Africa had dark skin with hair covering it because the sunlight is very strong When they moved to places where they could not get enough sunlight to 7 vitamin D their skin color became lighter Generally speaking people in areas with strong sunlight have darker skin 8 people in other areas have lighter skin 9 Melanin 10 an important role in our skin color With our living environment changing melanin production is changed which leads to the changes in our skin color 答案答案 基础