Vũ trụ có tuổi thọ khoảng 15 tỉ năm. Hỏi vũ trụ có bao nhiêu ngày tuổi (một năm có 365,5 ngày)? (Hãy viết dưới dạng kí hiệu khoa học) giúp đi

Vở sạch chữ đẹp Luyện viết chữ theo hình

Một vật chuyển động trên hai đoạn đường thẳng với các tốc độ v 1 và v 2 với v 1 ≠ v 2 . Định điều kiện để tốc độ trung bình trong cả hai đoạn đường bằng trung bình cộng của hai tốc độ đó?

Error identification and correction: 1. The future cars will fly around the building as planes, and they will be much faster. 2. People living in small towns often seem more friendly than those in populating densely areas. 3. Scientist found a casual relationship between intense exercise and motor neuron disease among those already susceptible by the disease. 4. Tourism is really thriving in Nha Trang, generated a lot of income for the local people.

Bài 1. Vật chuyển động thẳng đều từ A đến B với tốc độ 10m/s, AB = 100m. Lập phương trình chuyển động nếu: a. Gốc O trùng A, chiều dương hướng từ A sang B, gốc thời gian t 0 = 0 là lúc vật xuất phát? b. Gốc O trùng B, chiều dương hướng từ A sang B, gốc thời gian t 0 = 0 là lúc vật xuất phát? c. Gốc O trùng A, chiều dương hướng từ B sang A, gốc thời gian t 0 = 0 là lúc vật xuất phát?

Một cái sân hình chữ nhật có chiều rộng là x = 2,56m ± 0,01 m và chiều dài là y = 4,2 m ± 0,01 m. Chứng minh rằng chu vi P của sân là P = 13,52m ± 0,04 m. giúp đê

1. My parents were very strict _______ me when I was young. A. with B. for C. on D. of 2. He’s never been _______ trouble _______ his teachers before. A. at - to B. on - for C. under - of D. in - with 3. How could he be so tactless as to _______ funerals when her father’s just died? A. make jokes about B. take a joke C. get the joke D. see the joke 4. They always kept on good _______ with their next-door neighbors for the children’s sake. A. terms B. relations C. relationship D. will 5. He gets really jealous if his girlfriend _______ a friendship with another man. A. stamps out B. stretches away C. struggles on D. strikes up 6. Instead of simply punishing them, the system encourages offenders _______ their behavior. A. to modifying B. to modify C. modifying D. modify 7. I would _______ that guy if I were you, he has a screw loose. A. get away with B. throw out C. stay away from D. give away 8. She’s been promising _______ back the money for six months, but I reckon she’s just stringing me along. A. to pay B. paying C. to paying D. to be paid 9. Young college and university students _______ helping the poor who have suffered badly in wars or natural disasters. A. get involved in B. interfere with C. join hands D. come into 10. She decided to _______ the rat race because she couldn’t stand working 60 hours a week. A. come between B. hang over C. drop out of D. fall in with 11. _______ she’s going to realize what a mistake she’s made. A. At the end B. Sooner or later C. At last D. In time 12. It is imperative to meet face _______ face with the client. A. to B. by C. on D. with 13. Phil is always making snide comments, but I refuse to let him engage me _______ an argument. A. about B. of C. in D. into 14. Some of the patients were screaming and shouting _______ the nurse. A. to B. at C. with D. for 15. If you’re in a romantic _______ , you can make it easy to idealize your partner’s best traits. A. link B. bond C. relationship D. connection 16. If I had noticed him, I would have said hello _______ him. A. to B. upon C. for D. with 17. _______ are institutions of learning where students of the same gender are educated in different classrooms and schools. A. Single-sex schools B. Mixed Schools C. Eco-schools D. Co-educational schools 18. How do you _______ during boring lectures? A. stay away B. stay out C. stay on D. stay awake 19. He went to the cinema at least once a week, in the _______ of Susan or his young male friends. A. organization B. corporation C. company D. business 20. I’m so sad to hear that Mara _______ with John - I thought those two would be together forever. A. got out B. let out C. took in D. broke up 21. You couldn’t _______ any secrets even for an hour in that little town. A. keep B. get C. learn D. hear 22. I don’t have much _______ in him after his behavior in recent months. A. confidence B. self-confidence C. presumption D. pride 23. Tom really needed to _______ his inner fears to someone. A. show B. impress C. confide D. leak 24. We had to get permission from the city _______ an extension to our house. A. to building B. to build C. building D. being built 25. If you don’t want the job, there’s no end of people willing _______ your place. A. taking B. to be taken C. to have taken D. to take 26. I am now _______ with two of my estranged siblings - not just my older brother, but my sister, whom I hadn’t spoken to for 17 years. A. reconciled B. contactable C. truthful D. opposed 27. I’m sure your bank manager will lend you a _______ ear when you explain the situation to him. A. merciful B. sympathetic C. compassionate D. pitiful 28. It is wrong of you to judge other people by their _______ A. shape B. dimension C. appearance D. size 29. Knowing that my father is very rich, she tries to make _______ with me. A. compatriots B. peers C. friends D. colleagues 30. The drought has made farmers _______ about the harvest. A. worried B. curious C. anxious D. troubled 31. According to some stories, werewolves are people who _______ wolves every time there is a full moon. A. change over B. get down C. lead on D. turn into 32. I have a _______ with a girl I met recently tonight. A. date B. day C. daily D. time 33. My teacher always _______ me advice to choose suitable career in the future. A. takes B. gives C. seeks D. ignores 34. The sales assistants are trained to _______ customer complaints in a friendly manner. A. deal with B. keep down C. come around D. fit out 35. Any candidates caught _______ in the examination will be disqualified. A. cheating B. deceiving C. conjuring D. deluding

I.Put a suitable preposition in each blank 1.When did you meet him?_______lunch today 2.It often rains_____October_____in VietNam 3.What are you going to do____2020? 4.I don't know but i am going to go to college____September this year 5.You want to watch the sky_____sunset

Ghi kết quả thôi, thank trước ạ hứa đánh giá tốt theo yêu cầu

Cho 0,1 lít dung dịch NaOH 3M tác dụng vừa đủ với dung dịch Fe2(SO4)3 thu được kết tủa X. a, Tính khối lượng của X b, Cho toàn bộ lượng kết tủa trên vào 100 ml dung dịch HCl 2M . Hỏi kết tủa có tan hết không ?