Một hợp chất X gồm 2 nguyên tử Z liên kết với 5 nguyên tử O và có phân tử khối nặng hơn khí nitơ là 3,86 lần a) Xác định phân tử khối của hợp chất trên b)Xác định nguyên tử của Z,tên nguyên tố và hoá trị của X

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Read the following passage and choose the option (A, B, C or D) that best answers each of the questions below. What’s your hobby? Bill: Most people collect things and I’m no exception. I’ve been collecting posters since I was 9 years old. I’m now 14, so you can imagine how many posters I’ve got! I’ve got all sorts - from small ones I’ve found in magazines to very large ones I’ve bought at concerts or sporting events. My favourite poster is one that I have of my favorite film – The Lord of the Rings. It’s more than a meter high and I’ve put it up on my bedroom wall where I can see it when I’m lying in bed. Lauren: My hobby is my music. I sing and play the drums in an all-girl group. We started the group only last year, but we have already played five concerts – two of them at my school! Many people ask me how can I sing when I’m playing the drums. I don’t think it’s at all difficult. Of course I’m not the only singer in the group. Melissa, one of the guitarists, also sings. I really love my hobby and hope that when I grow up I will be in a famous band. 31. When did Bill start collecting posters? A. 5 years ago. B. last year. C. 9 years ago. D. When he was 14 years old. 32. Bill says he’s got posters _____. A. from all over the world B. from magazines only C. from concerts only D. of all sizes 33. The poster that Bill loves best is _____. A. on his bedroom wall B. a small one C. of his favourite group D. was a gift to him 34. How many singers are in Lauren’s band? A. One B. Two C. Three D. Five 35. When she’s older, Lauren says she would like to _____. A. stop playing in a band B. start a new instrument C. be a well-known musician D. attend more famous school