user-avatar
vannanhh98
2 năm trước
giúp mình với: Giải bài toán bằng cách lập hệ phương trình: 1) Hai tổ công nhân làm chung trong 12 giờ sẽ hoàn thành xong công việc đã định. Họ làm chung với nhau trong 4 giờ thì tổ 1 được điều đi làm việc khác, tổ 2 làm nốt công việc còn lại trong 10 giờ. Hỏi tổ 2 làm một mình thì sau bao nhiêu lâu sẽ hoàn thành công việc.
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

III/ CLOSE TEXT: Read the text and choose the best answer. (2 pts) A love of travelling For Nigel Portman, a love of travelling began with what’s (1)____ a ‘gap year’. In common with many other British teenagers, he chose to take a year out before (2)____ __ to study for his degree. After doing various jobs to (3)_____ some money, he left home to gain some experience of life in different cultures, visiting America and Asia. The more adventurous the young person, the (4)_____ the challenge they are likely to set themselves for the gap year, and for some, like Nigel, it can (5)______ in a thirst for adventure. Now that his university course has (6)_____ to an end, Nigel is just about to leave on a three-year trip that will take him right around the world. What’s more, he plans to make the whole journey using only means of transport which are (7)_____ by natural energy. In other words, he’ll be (8)______ mostly on bicycles and his own legs; and when there’s an ocean to cross, he won’t be taking a (9)______ cut by climbing aboard a plane, he’ll be joining the crew of a sailing ship (10)______ . As well as doing some mountain climbing and other outdoor pursuits along the way, Nigel hopes to pass on to the people he meets the environmental message that lies behind the whole idea. 1. A called B. named C. referred D. known 2. A. settling down B. getting up C. taking over d.holding back 3. A. achieve B. raise C. advance D. win 4. A. stronger B. wider C. greater D. deeper 5. A. result B. lead C. cause D. create 6. A. come B. turned C. reached D. brought 7. A. pulled B. charged C. forced D. powered 8. A. attempting B. using C. relying D. trying 9. A. quick B. short C. brief D. swift 10. A. anyway B. alike C. instead D. otherwise

I/ Choose the best answers. (3pts) 1. The company was started …………. in 1995, but its annual sales are already over $20 million. a. from beginning b. from scratch c. at first d. at large 2. I didn’t want to ………… on his telephone conversation a. break up b. break in c. break down d. break out 3. She walks around all day with her ………………... . She must be in love. a. head in the clouds b. chalk and cheese c. ins and outs d. bulls with their horns 4. We were ……… to our chairs, listening intently to every word. a. committed b. hooked c. glued d. connected 5. The heat from the ……….. car could be felt several metres away. A. blazing b. burning c. glancing d. flaming 6. Their children are also ……….. high risk ……… developing the disease. a. in/of b. at/with c. at/of d. on/of 7. Prepare food in advance to ensure you don’t miss ……… on the fun! a. in b. out c. with d. off 8. The new leisure ……….. includes a swimming pool, a sauna and a gym a. complexity b. complexion c. complexity d. complex 9. The butterflies in my ……………… almost kept me from going on stage and performing. a. heart b. stomach c. hand d. liver 10. My grandparents’ lake house was built in 1953. It was completely destroyed by the forest fire a. My grandparents’ lake house was built in 1953 and completely destroyed by the forest fire b. My grandparents’ lake house, built in 1953, was completely destroyed by the forest fire c. My grandparents’ lake house was built in 1953, so it was completely destroyed by the forest fire d. The forest fire destroyed my grandparents’ lake house was built in 1953.

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team