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Giải giúp em bài này với ạ. Em cảm ơn Cho tứ diện ABCD có AB, AC, AD vuông góc từng đôi một. Gọi H là trực tâm tam giác BCD. Chứng minh AH vuông góc với (BCD)
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IX. Find the mistakes in the following sentences: 1. Any kind of violence must not be allow at school 2. These medicine must keep out of children’s reach 3. The instruction must follow strictly by the students 4. In the case of pupil being absent from school, messages can leave on the answering machine before 7:30 am 5. These pill must not take if you are under 12 years old. X. Give the correct form of the words in brackets: 1. She faced .............................. because she not only had few friends but also was unwelcomed in that area ( lonely ) 2. That a woman becomes a ..................... has ever been considered to be weird, as people have assumed that this job is only for men ( firefight ) 3. Although she was aware of gender .................. in favor of boys, she applied for that position ( prefer ) 4. This university is ranked as one of the most successful institutions which have made ................. progress in gender equality ( consider ) 5. in order to eliminate gender inequality, domestic ................. need to be shared by both husband and wives ( responsible ) 6. The number of female ................... has increased sharply for the past few years ( enroll ) 7. My uncle is very .................... about rhinos. He has studied about them for a long time ( knowledge ) 8. By knowing their children’s strength and .................. parents can find appropriate strategies to educate them( weak ) 9. She contributed to the information of an ....................... for female pilots, gave advice to women on careers and helped inspire others ( organize ) 10. Even today, her life and career remain .................. to many people ( fascinate ) XI. Rearrange the words / phrases to make meaningful sentences: 1. equality / essay / an / gender / on / be / written / must / by / student / each 2. processed / will / when / these / files / be ? 3. a / course / finished / must / in / a / maximum / be / of / weeks / four 4. serious / obesity / be / health / considered / be / to / a / problem / can 5. achievements / in / information / technology / and / will / made / be / scientists / mor / by

VII. Finish each of the following sentences in such a way that it means the same as the sentence printed before it. 1. Somebody has to pick the visitors up from the airport ( up )  The visitors ......................................................................... from the airport 2. Why don’t they tell me about these changes earlier ? ( should )  I ..................................................................................... about these changes earlier/ 3. Luckily it wasn’t neccessary for Jim to take the exam again ( need )  Luckily Jim ..................................................................... the exam 4. In the end I had no choice but to get a lift with a colleague ( could )  In the end all ............................................................................. get a lift with a colleague 5. By law, all rear-seat passengers are obliged to wear seat-belts ( have )  By law, seat-belts ...................................................................... all rear-seat passengers 6. It may seem strange but I like stake cake ! ( as )  Strange ................................................................ I like stake cake ! 7. Visitors to the zoo are not allowed to feed the animals ( must )  The animals .......................................................by visitors to the zoo 8. I would have been better If he had told us his new address ( should )  He .................................................................................. his new address 9. Alice’s face turned bright red when the teacher asked her a question ( have )  Alice ................................................................................. embarrassed 10. The notice says you have to sign the form twice ( be )  The notice says the forms ............................................................. twice. VIII. Finish each of the following sentences in such a way that it means the same as the sentence printed before it. 1. It’s not neccessary for you to do the test  You .................................................................................................... 2. Nobody can deny that she has a beautiful voice  It ............................................................................................. 3. They will catch all the prisoners again tonight  all the prisoners ........................................................................ 4. They haven’t cleaned the street this week  The streets ....................................................................................... 5. He could repair the broken vase  The broken vase .............................................................................................. 6. The could not trace who had supplied the information in the first place  The course ......................................... 7. I gave Tom the message, but he already knew about it  I needn’t ....................................................................... 8. It’s a pity you didn’t come to the party because you’d have loved it  You .......................................................... 9. It is essential that no one be told about our plans  You ....................................................................................... 10. It was wrong of you not to call the doctor at once  You ....................................................................................

V. Read the following passage and mark the letter A,B,C or D on your answer sheet to indicate the correct answer to each of the questions from 1 to 10. Women in Families Role reversal has not really become popular. Couples who swap roles are still few and far between. Is that because women are better at rearing children? Or are men just afraid to resist tradition? The isolation was the worst thing, said Andrew Timpson, who left teaching to take care of his home and children for two and a half years. The idea of swapping roles-for the father to stay at home while mum goes out to work - is still a relatively new one. In the 70s it sounded like a great idea. Let the newly liberated women make progress with her career while the New Man stays at home and takes care of the house and children. Now, 10 years or so later, it seems as if we were a little premature. A recent report by the Family Policy Studies Center concludes: "Despite important social changes, particularly greater female employment, it is still women in families who undertake the great bulk of house-work, cooking, child-care and taking care of elderly relatives - The much hyped New Man remains a rare species.’ Certainly some would argue that a man cannot replace a mother - that mum is the natural homemaker, while dad is the provider. Some men might give help with shopping and cooking, but most would do little more. Some men even believe that doing housework is an insult to their masculinity. Others, like Andrew, want to stay at home-but with reservations. Andrew, who is now about to return to work, says, "I don't know that I could have continued doing it for the rest of my life. I enjoyed it, but I do want to support my family and I do want to work. I thought I could handle being dependent on Maureen, but it proved to be tough for both of us." Maureen says, "I've got a job I really love. Continuing working has allowed me to fulfill my potential." For many couples who swap roles, traditional attitudes are a major problem. Frank and Joan Roberts found that they were confronted with strong views when Frank left his job to look after Michael, five, while Joan continued with her career. Frank says, "It is not socially acceptable where we live. People here are reared to believe that the man goes out to work and woman stays at home." 1: According to the passage, that couples who change roles has been ........................... a. still rare b, very popular c. popular d. not happened 2: Which of the following is TRUE according to the passage? a..Women should not go out to work because they are better rearing children. b..Men don't want to change roles because they are traditionally weak. c..Andrew Timpson left teaching to take care of his home and children for two and a half year. d. Fathers have to stay at home to take care of their children because they are no longer the provider. 3: The Family Policy Studies Center concluded that_______ . a..at present, women still do most of the housework b..many women change their traditional roles, because there are many jobs created for them c..the men stay at home to take care of the house and children d..a and c are correct 4: In the last paragraph, Frank and Joan Roberts were confronted with strong views because ............... a..Frank went out to work and Joan Roberts looked after her child b..both of them went out to work c..Frank was unable to look after his child d..Frank left his job to look after his child, while his wife went on with her career. 5: The word “ swap ” in the passage most nearly means________ a. improve b. make better c. share d. change 6: Choose the best expression to replace the phrase “ fulfill my potential” in the passage. a. fulfill myself b. improve myself c. improve my potential d. gain success 7: The word “ major ” in the passage most nearly means________ a. big b. primary c. important d. best 8: Frank said that _________ a.. his society encourages men to stay at home to look after children b. men where he lives are brought up to do the housework c. it is very common for women to go out to work where he lives d. his society does not accept the fact that women go out to work while men stay at home 9 : The word “ resist ” in the passage most nearly means_____ a. follow b. oppose b. eliminate d. realize 10: The topic of this paragraph might be ________ a. stay-at-home fathers b. stay-at-home mothers c. taking care of children d. women's careers.

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