Một lò xo có chiều dài tự nhiên là 100 cm. a) Khi kéo lò xo bằng một lực 10 N thì lò xo dài 110 cm. Tìm độ cứng của lò xo? b) Khi nén lò xo bằng một lực là 20 N thì lò xo có chiều dài là bao nhiêu?

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1.Customer : _____ B. How much ________ are a sandwich and an ice-cream ?-Storekeeper : 35,000 dong A.How many B. How much C. What D. How 2.Son : Are there _____________ vegetables for lunch, Mom? Mom : Yes. There are some. A.any B. a C. some D. the 3.Can you go to the store ____________ me ? A.to B. on C. of D. for 4.Nga : Would you like some lemon juice, Nam ? Nam : __________________ Yes, I like B. No, I don’t. C. No, I would. D. Thanks, I’d love to. 5. Van : Do you want some sandwiches ? Thu : No, I’m not __________, thanks. A. hungry B. full C. thirsty D. good 6. My mother has an _______________ face . A. oval B. old C. small D. round 7.The boys has a small straight _________________ . A. nose B. eyes C. ear D. lips 8.You ___________ stop when the lights are red. A. can B. can’t C. must D. mustn’t 9.They travel from Hanoi __________ Ho Chi Minh city by train. A. on B. with C. to D. at 10.Salesgirl : How many oranges does she want ? Tina : ___________ of oranges A.Two kilo B. A dozen C. Half a dozen D. half a kilo 11. The sign warns you that…….. A. You must walk here. B. You must not ride a bike here. C. There are no bikes here. D. There are no vehicles here. 12. The sign noticed that…….. A. The students must cross here. B. The students must not run fast. C. A place for crossing is here, slow down and be aware. D. The students go ahead slowly. II. Supply the correct form of word given in each sentence: 1. I study English on the ________________________floor. (five) 2. There is an armchair in the ___________________ room. (live) 3. He gets _____________________ and goes to school. (dress) 4. She is my English ____________________. (teach) 5. We can’t ___________ into this road. ( going ) 6. My father _______________ any fish at this time. ( not, eat ) 7.Their parents work on the farm. They are _________________. ( farm ) 8. Her _______________ are small and white. ( tooth)