Cho tam giác ABC vuông tại A, biết : a, b =18 dm , c = 21 dm b, a = 20 cm , góc B = 35°

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Rewrite the sentences without changing their meanings 1. We pollute the water. We have no fresh water to use. ->If................................................................. 2. You cut down the trees in the forests. Therefore, there will be big floods every year. ->If ........................................................... 3. There is too much exhaust fume in the air, so more and more people will cope with respiratory problems. ->If ........................................................... 4. you can keep your neightbour clean. You will have an ideal place to live. ->If ........................................................... 5. People should stop using dynamite for fishing. A lot of sea creatures will be well preserved. ->If ........................................................... 6. We should save energy. ( use public transportation). -> I suggest ........................................................... 7. Why don't we use water economically? (use showers instead of baths) -> I suggest ........................................................... 8. The water pipes are too old. ( get some tools to check cracks) ->I suggest ........................................................... 9. These 100-watt light bulbs consume a lot of electricity. (use energy-saving bulbs) ->I suggest ........................................................... 10. this faucet is always dripping. (replace) ->I suggest ........................................................... 11. These disabled people are very poor. (raise money) ->I suggest ........................................................... 12. Look at this electricity bill; it is too high. (reduce the use of electricity) -> I suggest ...........................................................