user-avatar
chuquyk15
2 năm trước
Cho biết tâm thất trái mỗi lần co bóp đẩy đi được 74ml máu và một ngày đêm đấy được 7792 lít máu. Thời gian của pha giãn chung = 1/2 chu kỳ co, thời gian pha co tâm nhĩ = 1/3 thời gian pha co tâm thất.Hãy tính: a, Số mạch đập trong 1 phút ? b, Thời gian hoạt động của 1 chu kỳ tim c, thời gian của mỗi pha: co tâm nhĩ, co tâm thất, giãn chung là?
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

VII. Put the verbs into the correct form. Use Present Simple. 1. They ______________ (play) football and basketball at school. 2. My father ______________ (read) the newspaper every morning. 3. We ______________ (have) English, Maths and Science on Monday. 4. She never ______________(do) her homework. 5. I ______________ (go) swimming twice a week. 6. Cars ______________ (be) more expensive than motorbikes. 7. Jane always ______________ (have) breakfast at 6 o’clock. 8 He usually ______________ (watch) TV after dinner. 9. London ______________ (be) a very big country. 10. I ______________ (be) a student and my parents ______________ (be) teachers. . XI. Complete the sentence with the negative form of the present continuous. Use short forms. 1. They ________________ (help) the teacher right now. 2. She ________________ (stay) in a hotel. 3. I ________________ (travel) a lot these days. 4. We ________________ (study) science at present. 5. The children ________________ (play) football in the playground. 6. Bob ________________ (watch) the news on TV. 7. My parents ________________ (talk) to the teacher at the moment. 8. The sun ________________ (shine) today. XII. Complete the sentence with the present simple or present progressive form of the verb in brackets. 1. I ________________ (look) for Jack. Do you know where he is? 2. You ________________ (know) a lot about computers. 3. They ________________ (do) maths homework now. 4. Mark often ________________ (play) tennis at the weekend. 5. Just a minute, I can’t hear you. I ________________ (listen) to the radio. 6. Bob ________________ (watch) the news on TV every morning. 7. Be quiet! The children ________________ (study) in the room. 8. Mark ________________ (not do) homework on Saturdays. 9. Wake up! The teacher ________________ (ask) you a question. 10. We ________________ (not work) at the moment. We’re on a break. XIII. Complete the sentences with the question words. 1. does the first lesson begin? - At seven o’clock. 2. are you going? - To the library. 3. do you usually bring to school? - Textbooks, notebooks and pens. 4. do you go to school? - By bike. 5. is Mary talking to? - Mrs. Berry, her English teacher. 6. is your favorite subject? - Maths. 7. is your first day at school? - Oh, it’s great. 8. does Phong do judo? - Three times a week. 9. students are there in your class? - Forty. 10. pocket money do you get? - Ten thousand dong. D. READING I. Fill in each gap with a word from the box. Middle school often includes sixth, seventh, eighth and ninth (1) ____________. It’s calledmiddle school because it’s in the middle of your (2) ____________ years. Elementary school is behind you. High school (3) ____________ awaits you. For a kid, going to middle school is often a (4) ____________ change: First, it usually means moving to a new building, which takes some time to adjust to. (5) ____________, it may mean taking a different bus, with different students. Third, the friends you made in (6) ____________ school may end up going to different middle schools. And other things that probably will be different are the (7) ____________ and the work. All of that can make you feel a bit (8) ____________ on the first day of school. E. WRITING I. Put the words in order to make a sentence. 1. secondary/ first/ your/ at/ school/ is/ how/ week? 2. lessons/ many/ have/ on/ how/ you/ do/ Friday? 3. art/ creative/ are/ drawings/ students/ the/ some/ doing/ in/ club 4. school/ at/ English/ we/ have/ classes/ don’t/ today 5. homework/ you/ doing/ maths/ are/ your? 6. children/ first/ on/ most/ school/ excited/ are/ day/ of/ the II. Complete the second sentence so that it has the same meaning as the first. 1. What is your favorite subject? → What subject 2. There are 35 students in my class. → My class 3. Mai live near her school. → Mai’s house isn’t 4. Mary plays the piano very well. → Mary is good 5. Do you like physics? → Are you interested 6. The school has a computer room and a library. → There

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