1.FeS 2 + O2 −> SO2 + Fe 2O3 4FeS 2 + 11O2→8SO2 + 2Fe 2O3

2.Cu + HNO3 −> CU NO3 2 + NO + H2O 3Cu + 8HNO3→3Cu NO3 2 + 2NO + 4H2O 

3.CuSO4 + NaOH −> Cu OH 2 + Na 2 SO4 CuSO4 + 2NaOH→Cu OH 2 + Na 2 SO4

Các tuyến nội tiết của mối quan hệ nào với nhau ? 

Các tuyến nội tiết tiết ra hormone vào máu. Điều này cho phép các hormone di chuyển đến các tế bào ở các bộ phận khác của cơ thể.

Chúng có sự phối hợp hoạt động ra sao ?

- Các hormone nội tiết giúp kiểm soát tâm trạng, tăng trưởng và phát triển, cách các cơ quan của chúng ta hoạt động, sự trao đổi chất và tái sản xuất.

- Hệ thống nội tiết điều chỉnh lượng hormone được tiết ra. Điều này có thể phụ thuộc vào mức độ hormone đã có trong máu hoặc mức độ của các chất khác trong máu, như canxi. Nhiều thứ ảnh hưởng đến mức độ hormone, chẳng hạn như căng thẳng, nhiễm trùng và những thay đổi trong sự cân bằng của chất lỏng và khoáng chất trong máu.

It's true that there are a wide range of traffic problems in Vietnam. I think the main reason of these problems is that people's sense of road safety is not good. Firstly, there are too many vehicles on the road that leads to traffic jams, especially in the rush hour when people go out or get home. Secondly, there are traffic accidents every day so a lot of people are injured or lose their lives . Will reduce the population if it keeps going on.Another problem is that the road in our big cities are narrow and bumpy. They are easily flooded when it rains so heavily. In order to go on the roads safely, I think we should obey the traffic rules and traffic signs as well. i hope traffic in Vietnam will get better in the future

Enviroment is the most important thing for our life. Enviroment is the air we breath, the water we drink and is everything we need for our life. But now that most important thing for our life is being polluted and by many different ways. This pollution affects the health of living things. Air is damaged by car and lorry fumes, and power stations create acid rain which destroys entire forests and lakes. When fossil fuels i.e. oil, gas and coal are burned to provide energy for lighting, cooking etc. they form polluting gases. Not only on land but also in the sea, oils spills pollute sea water and kill marine life; chemical waste from factories and sewage works, and artificial fertilisers from farmland, pollute river water, killing wildlife and spreading disease. Everything is being caused by human’s existence. Humans create such a lot of rubbish! Each household produces about 1 tonne of rubbish every year! Most of this is taken away by dustmen and buried in enormous landfill sites or burned in incinerators - both of these actions can be dangerous for the environment. But only we can change it and solve it. Pollution can be prevented by thing we do everyday. First we can use recycled paper to help save trees. Second try to avoid buying plastic. It's hard to recycle. One way to cut down on plastic is to refuse to use carrier bags. If we can’t avoid buying plastic bags, we should use re-use plastic bags over and over again, until they wear out. Finally we should take your old clothes to charity shops, some are sold. To protect environment we also have to save energy. Use less energy by switching off lights when rooms are not in use, not wasting water; don’t forget to switch off all electric things when they are not in use, use a bicycle or walk instead of using a car for short trips we can save energy, keep clean atmosphere and keep healthy life. Lighting accounts for 10 percent to 15 percent of the electricity bill. However, this amount can be reduced by replacing an ordinary 100-watt light bulb with an energy-saving bulb and we still trying to invent the new thing to save money as well as conserve the Earth’s resources. Keep clean environment isn’t only all ways are mentioned before but also to protect natural resources. That is the way to conserver wild life. First we need to conserve the old forest, rainforest, build more safari and national park, and plant more trees to make place to live for wild animals. Second we need to prohibit hunters who hunt animals too many out of the law allowance. 

Tìm các từ phát âm "ed" đặc biệt

Being a volunteer is one of the best things you can do with your life. It's a great way to help other people. It's also very satisfying to know that you are not wasting your time and are helping people who need help.Many of us could and should be out there doing voluntary activities of some kind. So many volunteer organizations need extra hands. It really is easy. Just pick up the phone and offer your services.I think too many of us settle into a lazy lifestyle. We just want to come home and watch TV. Life is much more interesting when you're a volunteer.I've found it really opens your eyes to how some people live. It's sometimes sad to see how the government lets people down, but at least I'm doing my bit

a) Áo mẹ đã bạc màu => Mất màu, phai màu

b) Đừng xanh như lá bạc như vôi => Màu trắng bạc của vôi

Nghĩa đen: Ở miền Bắc nước ta, vào tháng bảy, tháng tám hàng năm thường có nhiều mưa, mưa rất to, mưa tầm tã, mưa nhiều ngày, gây ra bão, lũ lụt. Chỉ nhìn đàn kiến bò, 10 lượt kéo đi hàng đàn, nhân dân ta biết: sắp có mưa to, lũ lụt lớn sắp xảy ra

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