tính a=4+7+10....+n tính a biết dãy số 4;7;10.....+n đến chữ số thứ 10

Mn làm nhanh giúp mik nha nhưng phải đúng đó nhé Mik đag cần gấp

số liên kết hiđrô trong cặp A-T,G-X là bao nhiêu??

Hãy tóm tắt hoặc vẽ sơ đồ tư duy phần đại và hình chương 1 lớp 10

Làm cho mk 1 trong hai bài nha làm đc hết thì tốt

Rewrite the sentences using the suggested words / phrase without changing the original meaning

Hãy trình bày cảm nhận của anh chị khi mới bước vào mái trường Trung học phổ thông Not mạng nhá mấy bạn🙂🙂

vì sao dong mạch gỗ vận chuyển theo hướng đi lên còn mạch rây lại theo hướng đi xuống

1 I've hung out the clothes. It's lovely and sunny; if it (stay) like this they (be) dry in two hours. 2 French is essential in this job. All the telephonists speak it. If they (not know) French they (not understand) half the callers. 3 How did you do in the car rally? ~ We came in last actually; but only because we got lost. If we (not got) lost we (come) in somewhere in the middle. We certainly (not be) last. 4 I wasn't really surprised that we got lost because I knew that the navigator couldn't map-read. ~ But if you (know) that why you (take) him as navigator? 5 This flat would be all right if the people above us (not be) so noisy. 6 A group of spectators, including myself, left the stand just before the end of the game. When we were half way down the stairs a goal was scored and there was a great cheer from the spectators. If there (not be) a goal the crowd (not cheer). 7 If the crowd (not cheer) we (not run) back up the stairs to see what had happened. 8 If we (not run) back we (not crash) into the rest of the spectators on their way down, and there (not be) this frightful accident. 9 If the pain (return) you'd better take another pill. 10 If you aren't going to live in the house why you (not sell) it? If I (have) a house I couldn't use I (sell) it at once. 11 No, I didn't know any Russian at that time. ~ But if you (not know) Russian why you (offer) to give him Russian lessons? ~ Because I knew that he (refuse). He always rejected my offers. 12 Tell him to bring his bicycle inside. If he (leave) it outside someone (steal) it. 13 Why do people always wear dark clothes at night? If pedestrians (wear) light coloured clothes drivers (see) them much more easily. 14 She must have loved him very much because she waited for him for fifteen years. If she (not love) him she (not wait) so long. 15 He looked so small and weak that nobody asked him to do anything. If he (look) strong he (be) expected to dig all day like everyone else.

1. Khi hòa tan hoàn toàn một lượng một hỗn hợp gồm Zn , ZnO bằng dung dịch H2SO4 loãng vừa đủ thu đc dung dịch X trong đó số nguyên tử H bằng `60/29`số nguyên tử O . Tính C% CHẤT tan trong dung dịch X 1. Khi hòa tan hoàn toàn một lượng một hỗn hợp gồm Mg , MgO bằng dung dịch H2SO4 loãng vừa đủ thu đc dung dịch X trong đó số nguyên tử H bằng `50/26`số nguyên tử O . Tính C% chất tan trong dung dịch X