Một mẩu hợp kim thiếc và chì có khối lượng 664g, khối lượng riêng D = 8.3g/cm3. Xác định khối lượng thiếc và chì trong hợp kim. Biết D thiếc =7,3 g/m³ , D chì=11,3 g/m³ . Biết rằng thể tích của hợp kim bằng 0,5 % tổng thể tích các kim loại thành phần

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III. Give advice with “should” or “shouldn’t”, using the words given in brackets. Example: You look very pale and terrible. (see a doctor) You should see a doctor. 1. You work until 11 every night. (not work so hard) @ ………………………………………………………………………………… 2.It's Mai's birthday on Saturday. I think we should do something. (buy her a nice birthday present) @ ……………………………………………………………………………… 3.The car did not start this morning. (take it to the garage) @ ………………………………………………………………………………… 4.Our train leaves at 6 o’clock tomorrow morning. (go to bed early tonight) @ ………………………………………………………………………………… 5.He always gives you the wrong advice. (not listen to him) @ ………………………………………………………………………………… 6.Everything will be all right. (not worry so much) @ ………………………………………………………………………………… 7.He doesn’t like this job because it’s so boring. (look for another one) @ ………………………………………………………………………………… 8.It’s so late to play music so loudly, we’ll wake up the neighbours. (turn it off) @ ………………………………………………………………………………… 9.Your hair is so long. (have a haircut) @ ………………………………………………………………………………… 10.He doesn’t understand the lesson. (meet the teacher after class) @ ………………………………………………………………………………… IV. You the following set of words and phrases to write complete sentences. 1. People/ decorate/ homes/ plants/ flowers. @ ………………………………………………………………………………… 2. .People/ try/nice/ polite/ each other/ because/ they/ want/good luck/ New Year's Day. @ ………………………………………………………………………………… 3.They/ visit/ relatives/ friends/ they/ exchange/ New Year's wishes. @ ………………………………………………………………………………… 4 .Many people/ go/ pagoda/ have/ happy year/ their family. @ ………………………………………………………………………………… 5.Tet/ a time/ fun/ festivals/ throughout/ country. @ …………………………………………………………………………………