Một tàu hoả đang di chuyển với vận tốc 54 km/h thì tài xế hãm phanh để xe chuyển động chậm dần đều. Sau khi đi thêm được 50m thì vận tốc của nó là 36km/h a) Tính gia tốc của tàu b) Tính quãng đường mà đoàn tàu đi được kể từ khi phanh đến khi nó dừng lại C) Tính vận tốc của đoàn tàu khi nó đi được 25m kể từ khi bắt đầu hãm phanh

1. If you are not careful, you will cut yourself with that knife. A. Unless you are careful, you will cut yourself with that knife. B. If you are careful, you will cut yourself with that knife. C. Unless you are not careful, you will cut yourself with that knife. D. Unless you were careful, you will cut yourself with that knife. 2. Because he doesn’t leave immediately, I call a policeman. A. Unless he leaves immediately, I won’t call a policeman. B. If he leaves immediately, I won’t call a policeman. C. Unless he leaves immediately, I will call a policeman. D. If he left immediately, I wouldn’t call a policeman. 3. Today isn’t Sunday, so the pupils can’t go swimming. A. If today is Sunday, the pupils could go swimming. B. If today were Sunday, the pupils could go swimming. C. The pupils could go swimming unless today is Sunday. D. The pupils could not go swimming if today isn’t Sunday. 4. Stop talking or you won’t understand the lesson. A. If you don’t stop talking, you won’t understand the lesson. B. If you don’t stop talking, you wouldn’t understand the lesson. C. If you hadn’t stopped talking, you wouldn’t understand the lesson. D. If you hadn’t stopped talking, you wouldn’t have understood the lesson. 5. If the homework is difficult, I will ask you for help. A. Unless the homework is easy, I won’t ask you for help. B. Unless the homework is difficult, I will ask you for help. C. Unless the homework is easy, I will ask you for help. D. Unless the homework isn’t difficult, I won’t ask you for help. 6. I’ll let you borrow the book but you must promise to return it next week. A. If you promise to return the book, I let you borrow it. B. If you promised to return the book, I’ll let you borrow it. C. If you promise to return the book next week, I’ll let you borrow it. D. If you promise to return the book next week, I won’t let you borrow it.

Chứng minh biểu thức bên dưới có giá trị là 1.

Một người đi xe đạp thẳng đều trong 2s đi đước 20m. Vậy ng đó đi dc 60m trong bao lâu???

CM : 3 điểm phân biệt A,B,C thẳng hàng <=> vecto AB cùng hướng vs vecto AC

. Thực hiện phản ứng tráng gương hoàn toàn 17,4 gam một andehit đơn chức X thu được 64,8g Ag. CTCT X là:

Điều kiện tự nhiên xh của VN ảnh hưởng ntn đến sự phát triển nông lâm ngư nghiệp?

Giúp tớ với,mai tớ phải nộp rồi

TỔng của ba số là 1356.Biết trung bình cộng của số thứ nhất và số thứ hai là số bé nhất có ba chữ số khác nhau.Tìm số thứ ba?

1. REPORTED STATEMENTS 1. ”We have moved into our new flat". My friend said 2. Japan is a densely populated city". The teacher said 3. “My parents have already seen this film”. He said 4. "I know exactly what she did yesterday". He told me 5. "My sister is working now”. He said 6. "I'll help you with those exercises tomorrow". Tony said 7. “I was waiting for the bus when he arrived”. She told me 8. “I didn’t go to the party”. She said 9. “We must see these movies tonight”. They said 10. ”I am sure I saw you here last week.” My father told Ben