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24 tháng 3 2022

Tham khảo:

Theo quy ước, oxy có khối lượng mol là 32g, trong đó không khí có khối lượng mol 29g. Như vậy, oxy nặng hơn không khí theo tỷ lệ 32/29, tương đương 1,1 lần. Đây cũng là lý do mà không khi càng trên cao, oxy càng loãng, khiến cho việc hô hấp, trao đổi chất của cơ thể trở nên khó khăn hơn.

24 tháng 3 2022

Vì khí oxi giúp cho bệnh nhân thở tốt hơn. Trong kk chỉ có 21% là khí oxi nên thở bằng bình oxi tốt hơn kk

3 tháng 4 2022

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28 tháng 10 2021

30. C

31. D

32. B

15 tháng 5 2019

Chọn đáp án B

Mạch gốc của gen là 5’AGXAGXXXXGGG3’ thì chúng ta viết đảo lại mạch gốc thành: 3’GGGXXXXGAXGA5’.

- Mạch ARN tương ứng là: 5’XXXGGGGXUGXU3’.

- Trong quá trình dịch mã, mỗi bộ ba trên mARN quy định 1 aa trên chuỗi polipeptit

Trình tự các bộ ba trên mARN là 5’XXXGGGGXUGXU3’

Trình tự các aa tương ứng là Pro – Gly – Ala – Ala.

8 tháng 8 2018

PASSIVE VOICE

Exercise 1. Make the sentences passive:

1. Somebody cleans the office every day.

2. Somebody sends emails.

3. Somebody cuts the grass.

4. Somebody prefers chocolate.

5. Somebody often steals cars.

6. Somebody plays loud music.

7. Somebody speaks English here.

8. Somebody loves the London parks.

9. Somebody wants staff.

10. Somebody writes articles.

11. People speak Portuguese in Brazil.

12. The Government is planning a new road near my house.

13. My grandfather built this house in 1943.

14. Picasso was painting Guernica at that time.

15. The cleaner has cleaned the office.

16. He had written three books before 1867.

17. John will tell you later.

18. By this time tomorrow we will have signed the deal.

19. Somebody should do the work.

20. The traffic might have delayed Jimmy.

21. Everybody loves Mr Brown.

22. They are building a new stadium near the station.

23. The wolf ate the princess.

24. At six o’clock someone was telling a story.

25. Somebody has drunk all the milk!

26. I had cleaned all the windows before the storm.

27. A workman will repair the computer tomorrow.

28. By next year the students will have studied the passive.

29. James might cook dinner.

30. Somebody must have taken my wallet.

Exercise 2:

The Passive: Verbs with Two Objects This time there are two answers:

1. John gave a bar of chocolate to Jill.

a:

b:

2. I lent a pencil to Graham.

a:

b:

3. Fiona told the truth to Julian.

a:

b:

4. They offered the job to Simon.

a:

b:

5. The boss showed the new computer to Anna.

a: _

b:

6. Julie taught the grammar to the students.

a:

b:

7. I sent the email to John.

a:

b:

8. Lucy threw the ball to the child.

a:

b:

9. Sophia sold the car to a doctor.

a:

b:

10. I asked the question to David.

a:

b:

1) People think that the new prime minister is a good speaker.

It is ……………………………………………………………………………………

The new prime minister ………………………………………………………………

2) They report that the suspended gunman is in custody.

The suspended ………………………………………………………………………

It is ……………………………………………………………………………………

3) People don't expect that the new party will win the election.

It isn't ……………………………………………………………………………………

The new ……………………………………………………………………………………

4) The police say that the principal is at large.

It is ……………………………………………………………………………………

The principal ………………………………………………………………………………

5) The detective knows that the robber has left the city.

It is ……………………………………………………………………………………

The robber ……………………………………………………………………………

6) People believe that giving encouragement is important at work, too.

It is ……………………………………………………………………………………

Giving encouragement ………………………………………………………………

7) They told us that Charles drank too much at the party.

It was ……………………………………………………………………………………

Charles ……………………………………………………………………………………

8) People know that drug addiction is dangerous.

It is ……………………………………………………………………………………

9) They believe that the lunch will be delicious.

The lunch is …………………………………………………………………………………

10) They think that the children are at school.

The children …………………………………………………………………………………

11) People said that the robbery lasted half an hour.

It is ……………………………………………………………………………………

12) People acknowledge that he is talented.

He is ……………………………………………………………………………………

13) The newspapers reported that he won the jackpot.

He was ……………………………………………………………………………………

14) They think that your tea is too sweet.

It is ……………………………………………………………………………………

15) Everybody says the old bridge will collapse.

The old ……………………………………………………………………………………

16) It is said that the thief stole several wallets.

The thief is …………………………………………………………………………………

17) People think that the pigeons carry a lot of diseases.

It is ……………………………………………………………………………………

18) Sarah is known to be the prettiest girl in the class.

It is ……………………………………………………………………………………

19) It was understood that he got divorced.

He was ……………………………………………………………………………………

20) Amy Winehouse was reported to have died.

It was ……………………………………………………………………………………

21) It is acknowledged that she is a talented painter.

She is ……………………………………………………………………………………

22) The Sun was believed to move round the Earth.

It was ……………………………………………………………………………………

23) It is said that the pilot was drunken.

The pilot ……………………………………………………………………………………

24) This kind of material is found to be poisonous.

It is ……………………………………………………………………………………

25) The witness was thought to have injured.

It was ……………………………………………………………………………………

IV. YES/NO & WH QUESTIONS

1. Does your brother find the key?

2. Do you sweep the floor?

3. Can your father finish the report?

4. Which horses do you prefer?

5. What song do the clowns sing?

6. Who cleaned my room yesterday?

7. Do you steal my pencil case?

8. Which animals do you like?

9. Who broke my glasses?

10. Did he explain that lesson?

11. Where this you buy this book?

12. Why does your father find you?

13. When do you paint your house?

14. Do you paint your house?

15. Didn’t she find a job?

16. Will your granny visit you?

17. Do they wash the dishes?

18. Where do they wash the dishes?

19. When do they wash the dishes?

20. Why will your granny visit you next week?

8 tháng 8 2018

Ex1:

1.The office is cleaned every day.

2.Emails are sent.

3.The grass is cut.

4.Chocolate is preferred.

5.Cars are often stolen.

6.Loud music is played.

7.English is spoken here.

8.The London parka are loved.

9.Staff is wanted.

10.Articles are written.

11.Portuguese In Brazil are spoken.

12.A new road near my house is being planned by the government

25 tháng 2 2018

Đáp án A

Chuỗi Phe – Gli - Asn - Pro được mã hóa bởi đoạn mARN có trình tự 5’…UUU GGG AAU XXX..3’

Vậy đoạn mã gốc trên gen là: 3’…AAA XXX TTA GGG…5’

14 tháng 12 2021

m - ( -n + p - q ) = m + n - p + q

⇒ Đáp án:     D

21 tháng 11 2018

nền văn hóa Đông Sơn nhé,còn giải thik thì ................ờ ờ...................thôi chịu

15 tháng 3 2022

Cái cây ấy đang loay hoay tìm bạn

15 tháng 3 2022

Em hãy đặt 1 câu kể "Ai làm gì ?" có sử dụng biện pháp nghệ thuật nhân hóa ?

.........................Chị Ong đang chăm chỉ kiếm mật hoa .làm đẹp cho đời..

Câu 17:

a) PTHH: \(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)

b+c) Ta có: \(n_{Mg}=\dfrac{3,6}{24}=0,15\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{HCl}=0,3\left(mol\right)\\n_{H_2}=0,15\left(mol\right)=n_{MgCl_2}\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\\m_{ddHCl}=\dfrac{0,3\cdot36,5}{14,6\%}=75\left(g\right)\\m_{H_2}=0,15\cdot2=0,3\left(g\right)\\m_{MgCl_2}=0,15\cdot95=14,25\left(g\right)\end{matrix}\right.\)

d) Ta có: \(m_{dd}=m_{Mg}+m_{ddHCl}-m_{H_2}=78,3\left(g\right)\)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{14,25}{78,3}\cdot100\%\approx18,2\%\)

19 tháng 5 2021

a) $Mg + 2HCl \to MgCl_2  + H_2$
b) n H2 = n Mg = 3,6/24  = 0,15(mol)

V H2 = 0,15.22,4 = 3,36 lít

c) n HCl = 2n Mg = 0,3(mol)

=> m dd HCl = 0,3.36,5/14,6% = 75(gam)

d)

n MgCl2 = n Mg = 0,15(mol)

Sau phản ứng : 

m dd = m Mg + mdd HCl - m H2 = 3,6 + 75 - 0,15.2 = 78,3(gam)

C% MgCl2 = 0,15.95/78,3   .100% = 18,2%