Hạt nhân nguyên tử gồm A. proton và electron. B. proton và nơtron. C. nơtron và electron. D. proton, nơtron và electron.

1: cho phân số 1+2+3+.....+8+9/11+12+13+......+24+25 Có thể xóa ở tử số nhiều nhất bao nhiêu số hạng, ở mẫu số nhiều nhất bao nhiêu số hạng để giá trị không thay đổi. 2: cho hình chữ nhật ABCD có I là trung điểm của AB, Nối DI, CI, DB. DB cắt CI tại K. Tính S ABCD biết S AIKD=20cm2

Làm bài 1.301 làm thêm trường hợp ngược dòng

Trộn V1 lit dung dịch H2SO4 0,3M với V2 lít dung dịch NaOH 0,4M thu được 0,6 lít dung dịch A. Tính V1, V2. Biết rằng 0,6 lít dung dịch A hoà tan vừa đủ 0,72 gam Mg và các phản ứng xảy ra hoàn toàn.

GIUP E VOI, e dang can gap TT e cam on

Caill :Bác Quân Nhất Tiêu màu vàng ,trang trí,trady caro

Calli: Drama ~~~hong drama khong dam ngu =)))

my little daughter is interested... dancing điền vào chỗ trống

Hòa tan hoàn toàn oxit kim loại M (II) cần 1 lượng vừa đủ đ H2SO4 4.9 % thu được dd muối có nồng độ 5.87 %. Tìm KL M Giúp em với ạ

Câu điều kiện 1,2 1. If we meet at 9:30, we (have) _________________plenty of time. 2. If you (find) _________________ a skeleton in the cellar, don’t mention it to anyone. 3. If you pass your examination, we (have) _________________a celebration. 4. Lisa would find the milk if she (look) _________________ for it in the fridge. 5. What (happen) _________________if I press this button? 6. The door will be unlocked if you (press)_________________ the green button. 7. If you go to Paris, where you (stay) _________________? 8. If you (swim) _________________ in this lake, you’ll shiver from cold. 9. If someone offered to buy you one of those rings, which you (choose) _________________? 10. If the milkman (come) _________________, tell him to leave two pints. 1. Someone (sit) _________________on your glasses if you leave them there. 2. You would hear my explanation if you (not talk) _________________so much. 3. What I (do) _________________if I hear the burglar alarm? 4. I would repair the roof myself if I (have) _________________a long ladder. 5. Unless they turn that radio off, I (go) _________________mad. 6. If you were made redundant, what you (do) _________________? 7. We’ll have a long way to walk if we (run) _________________out of petrol here. 8. If you shake that bottle of port, it (not be) _________________ fit to drink. 9. If you spoke louder, your classmates (understand) _________________ you. 10. I’ll probably get lost unless he (come) _________________with me. 11. You (not have) _________________ so many accidents if you drove more slowly. 12. What would happen if you ……………..to work tomorrow? a. don’t go b. didn’t go c. won’t go d. wouldn’t go. 13. We ‘ll get wet if we ………….out. a. go b. did go c. went d. had gone. 14. If I go shopping, I ………some food. a. buy b. will buy c. would buy d. would have bought. 14. If I find it, I ………you. a. will tell b. would tell c. had told d. told. 15. What would you do if you……………a million dollars? a. would win b. win c. had won d. won. 16. They ‘d be hurt if I ………………. a. don’t go b. didn’t go c. hadn’t gone d. wouldn’t go. 17. If we took the 6: 30 train, we…………too early. a. would have arrived b. arrived c. will arrived d. would arrive. 18. You won’t pass the examination……………you study more. a. as long as b. unless= if not c. if d. whether. 19. If I were to leave my country , I ……………disappointed. a. probably be b. would have been c. will be d. would be. 20. If I were in your place, I ……….a trip to England. a. will make b. had made c. made. d. would make. 21. If I ………….. you , I’d save some of your lottery winning. a. be b. were c. am d. was 22. If I had enough money, I ……… abroad to improve my English. a. will go b. should go c. would go d. should have go to 23. If it …….. convenient, let’s go out for a drink tonight. a. be b. was c. were d. is 24. If you ……. time, please write to me. a. have b. have had c. had d. has 25. If you had the chance, ………… you go finishing? a. did b. would c. may d. do 26. Trees won’t grow ……….. there is enough water. a. if b. when c. unless d. as III. Rewrite the following sentences using if 1. He can’t go out because he has to study for his exam. If 2. She is lazy so she can’t pass the exam. à 3. He will pay me tonight; I will have enough money to buy a car. à 4. He smokes too much; that’s why he can’t get rid of ( loại bỏ )his cough. à 5. She is very shy, so she doesn’t enjoy the party.