Bài tập 3: Cùng một lúc 2 xe xuất phát từ 2 địa điểm A và B cách nhau 60km, chúng chuyển động thẳng đều và cùng chiều từ A đến B. Xe thứ nhất đi từ A với vận tốc 30km/h, xe thứ hai đi từ B với vận tốc 40km/h a) Tìm khoảng cách giữa 2 xe sau 30 phút kể từ lúc xuất phát b) Hại xe có gặp nhau không? Tại sao?

cần gấp ạ ------------------------

Giúp mik với bài iv .Xong mik vote 5 sao

Giải giúp mình câu 29 với ạ. Rõ ràng nha. Mình cảm ơn.

6. Mary rang hours and hours. It is.................................................................................................................................... 7. He failed to win the race. He didn't........................................................................................................................... 8. She planted that tree five years ago. That tree............................................................................................................................ 9. My family has someone water the roses every day. My family has the.......................................................................................... 10. The rain began to fall during my walk in the country. While.................................................................................................................................

Before Stone Age, people used to eat fruits, leaves and anything they foundfrom the forest. However, this habit changed into hunting animals, preserving fooditems and planting and growing vegetables, which eventually led into farmingdifferent crops like maize corn, and rice. People were healthy, they rarely haddiseases and never needed extra exercise because their daily work kept their bodiesrunning.At present, we have turned the agriculture into a mass scale production,including machinery, technology and pesticides, all of which came in with thegreen revolution. With green revolution agriculture and the traditional farmingculture turned upside down. As far nor now, farmers who are able to cope up withthe multinational cooperation's and their large-scale, expensive products,pesticides and high-yielding varieties of seeds, keep producing crops for themarket. Yet the traditional, low-income farmers even today, especially in Asiancountries, are in a dire state.Fast food is another major factor in modern food habits. Although many peoplefind it convenient, it leads to many health conditions. Today people are unhealthy,needs medicine and functions on diets and exercise machines.A. Decide whether the following sentences are true (T) or false (F).1. People in the past ate healthy food so they rarely had diseases.Changes in Food Habits2. The green revolution is the decrease in agriculture production.3. The green revolution caused agriculture to change completely.4. Farmers nowadays can't meet the great demand of the food market.5. Fast food is convenient but it's not good for health.B. Answer the following questions.6. In the past, why didn't people need extra exercise?7. Who is still in the serious situation despite the development in agriculture?8. How are people nowadays compared to those in the past?

1. Mary no longer prepares for the wedding parties Mary doesn't................................................................................................................. 2. Who owns this motorcycle? Who does........................................................................................................................? 3. How long have John and Mary been married? When did........................................................................................................................ 4. Remember to check for spelling mistakes before you hand in your composition. Don't.............................................................................................................................. 5. The sea was too rough for the children to go swimming The sea was so................................................................................................................

Cali chữ: đã thi xong ( màu tím ; bằng tay )

1. Mary typed letters in the office. …………………………………………………………….. 2. His father helped you every day……………………………………………………….. 3. Science and technology changed human life. ………………………………………………………………………………….. 4. Peter broke this bottle. ………………………………………….. 5. They learned English in the room. ………………………………………………………………………………….. 6. He changed my mind.……………………………………………………….. 7. She tells me about it . ………………………………………………………………………………….. 8. I didn’t know her telephone number ………………………………………………………………………………….. 9. My students brought the children home. ………………………………………………………………………………….. 10. They sent me a present last week. …………………………………………………………………………………..

($\dfrac{1}{\sqrt{x}-1}$`-`$\dfrac{1}{\sqrt{x}}$):($\dfrac{\sqrt{x}+1}{\sqrt{x}+3}$+$\dfrac{\sqrt{x}+3}{\sqrt{x}-1}$) a)rút gọn b)tìm gtri A<0