Một người đi xe máy trên đoạn đường s = 5km, lực cản trung bình là 70N. Công của lực kéo động cơ trên đoạn đường đó là bao nhiêu? Biết xe chuyển động đều trên đường

A. A = 350J

B. A = 35000J

C. A = 3500J

D. A = 350000J

Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Orbis is an organisation which helps blind people of everywhere. It has built an eye hospital inside an aeroplane and flown it all over the world with an international medica team. Samantha Graham, a fourteen-year-old schoolgirl from England, went with the plane to Mongolia. Samantha tells the story of the Eukhtuul, a young Mongolian girl.

‘Last year, when Eukhtuul was walking home from school, she was attacked by boys with sticks and her eyes were badly damaged. Dr. Duffey, an Orbis doctor, said that without an operation she would never see again. I thought about all the things I do that she couldn’t, things like reading schoolbooks, watching television, seeing friends, and I realised how lucky I am.’

‘The Orbis team agreed to operate on Eukhtuul and I was allowed to watch, together with some Mongolian medical students. I prayed the operation would be successful. The next day I waited nervously with Eukhtuul while Dr. Duffey removed her bandages. “In six months your sight will be back to normal,” he said. Eukhtuul smiled, her mother cried, and I had to wipe away some tears, too!’

Now Eukhtuul wants to study hard to become a doctor. Her whole future has changed thanks to a simple operation. We should all think more about how much our sight means to us.’

The word "she" in the passage refers to ____.

A. the writer

B. the nurse

C. Eukhtuul

D. the medical studen

mình thiếu là 0,4:10=0,04

trọng lượng:p=10.m

=>khối lượng sẽ là:m=p:10

1 cục tẩy ; 1 tờ giấy và 1cây nến

Rút gọn các phân thức sau 2 a 2 - 2 a b a c + a d - b c - b d

khối lượng riêng:\(\dfrac{m}{V}\)

trọng lượng riêng:\(\dfrac{P}{V}\)