Bánh xe lớn của một đầu máy xe lửa có đường kính là 1,9 m Tính chu vi của bánh xe đó

Hòa tan hoàn toàn 4g hỗn hợp gồm 1 kim loại hóa trị II và một kim loại hóa trị III cần dùng hết 0,34 mol HCl. a)Tính thể tích Hiđro thoát ra ở đktc b)Cô cạn dung dịch thu được bao nhiêu gam muối khan c)Nếu biết kim loại hóa trị III là Al và số mol bằng 5 lần số mol kim loại hóa trị II thì kim loại hóa trị II là nguyên tố nào

Giúp e m với ạ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 1. If I (to come) ____________ home earlier, I (to prepare) ______________ dinner. 2. If we (to live) ______________ in Rome, Francesco (to visit) ____________ us. 3. If Tim and Tom (to be) ___________ older, they (to play) ___________ in our hockey team. 4. If he (to be) ______________ my friend, I (to invite) _____________ him to my birthday party. 5. If Susan (to study) ________________ harder, she (to be) ______________ better at school. 6. If they (to have) ______________ enough money, they (to buy) ______________ a new car. 7. If you (to do) _____________ a paper round, you (to earn) _____________ a little extra money. 8. If Michael (to get) _____________ more pocket money, he (to ask) _____________ Doris out for dinner. 9. If we (to hurry) ___________, we (to catch) _____________ the bus. 10. If it (to rain) ______________, Nina (to take) ______________ an umbrella with her. PART 2 1. He (come) _______ if you waited. 2. If you (ring) _______ the bell, the servant would come. 3. If it (not, rain) _______ a lot, the rice crop wouln’t grow. 4. If today (be) _______ Sunday, we wouldn’t have to work 5. You would have to stay in bed unless your health (improve) _______. 6. If I (not have) ________ a typewriter, I could type it myself. 7. What (you do) ________ if you got fat ? 8. They would not be paid unless they (do) _______________ their work well. 9. If I became very rich, I (build) _______________ a hospital for the poor. 10. If he (give) _______________ up smoking, as his doctor orders, he will be soon well again. 11. You would have to stay in bed unless your health (improve) _______________. 12. If I (have) ________________ a typewriter, I could type it myself. 13. You could make much progress if you (attend) ________________ class regularly. 14. If I (know) ________________ his telephone number, I would give it to you. 15. If he (study) ________________ harder, he can pass an exam. PART 3 1. If I (have) ________________ a typewriter, I could type it myself. 2. You could make much progress if you (attend) ________________ class regularly. 3.If I (know) ________________ his telephone number, I would give it to you. 4. If you are kind to me, I (be) _______________ good to you. 5. He (come) _______________ if you waited. 6. If he (study) ________________ harder, he can pass an exam. 7. She may be late if she (not hurry) ________________. 8. What (you do) ________________ if you got fat? 9. f you (ring) _______________ the bell, the servant would come. 10. If it (not, rain) _______________ a lot, the rice crop wouldn’t grow.

Tìm hoá trị của R trong hợp chất RxOy Viết phương trình phản ứng của R với HCl Làm giúp e bài này với e cần gấp lắm ạ

Cho phương trình: ( 1 – m)x = m - 1 (1) Giải và biện luận phương trình (1)

Mn người giải giúp em đề 2 vs ạ !!!!!!!!!! Em cảm ơn trước

Giúp em bài này với ạ! Cảm ơn nhiều!!!!!!!!!!!!!!!!!!!!!! XV Rewrite the following sentences based on the given words. ​1.​People don’t care much about environment, so they keep making it worse. ​→​If people ​ ​2.​She suffered from a serious disease because of drinking contaminated water in a long time. ​→​Since ​ ​3.​The drainage system is damaged. There is not enough water for the crop. ​→​If the drainage system ​ ​4.​“Why don’t you turn off more lights in the house to reduce your eyestrain?” ​→​If I ​ ​5.​The improvements of the public transport system will encourage more people to use it. →​If

Trong tinh thể nêu khái niệm ô cơ sở ,số phối trí ,số đơn vị cấu trúc

a)tính đường kính hình tròn có chi c=15,7m b) tính bán kính hình tròn có chu vi c=18,84dm

tính tổng S= 9+99+.....+99....9 ( n số 9 ) S = 7+77+......+77...7 ( n số 7 )