Hoa là một thể thống nhất vì:

- Có sự phù hợp giữa cấu tạo và chức năng trong mỗi cơ quan
- Có sự thống nhất giữa chức năng của các cơ quan.
- Tác động vào 1 cơ quan sẽ ảnhhưởng đến cơ quan khác và toàn bộ cây.
Ví dụ : Khi lá hoạt động yếu, thoát hơi nước ít thì sự hút nướccủa rễ cũng giảm, sự quang hợp của lá yếu không cung cấp đủ chất dinh dưỡng cho thân, rễ, nên cây sinh trưởng chậm và ảnhhưởng đến sự ra hoa, kết quả và tạo hạt.

\(x\times\dfrac{20}{11}=\dfrac{1}{1}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{11}\\ x\times\dfrac{20}{11}=\dfrac{10}{11}\\ \Rightarrow x=\dfrac{1}{2}\)

Ta có :

=> X x 20/11 = ( 1 - 1/3 ) + ( 1/3 - 1/5 ) + ( 1/5 - 1/7 ) + ( 1/7 - 1/9 ) + ( 1/9 + 1/ 11 )

=> X x 2/11 = 1 - 1/11 = X x 1/11 = 11/11 - 1/11

=> X x 20/11 = 10/11

=> X = 10/11 : 20/11

=> X = 1/2

\(Xx\dfrac{20}{11}=\dfrac{2}{1}-\dfrac{2}{3}+\dfrac{2}{3}-\dfrac{2}{5}+\dfrac{2}{5}-\dfrac{2}{7}+\dfrac{2}{7}-\dfrac{2}{9}+\dfrac{2}{9}-\dfrac{2}{11}\)

\(Xx\dfrac{20}{11}=\dfrac{2}{1}-\dfrac{2}{11}\)

\(Xx\dfrac{20}{11}=\dfrac{20}{11}\)

\(X=\dfrac{20}{11}:\dfrac{20}{11}\)

\(X=1\)

vậy X = 1

1 They accused Tom of stealing his money

2 She thanked me for my help

3 She apologized for not being able to help me

tưởng bảo không vào nữa

Hỗn hợp Cu, Fe, Al tác dụng với HNO3 đặc nguội => Chỉ có Cu phản ứng vì HNO3 đặc nguội gây thụ động với Fe và Al nên không tác dụng với chúng

\(Cu\rightarrow Cu^{2+}+2e\)   

\(2H^++NO_3^-+1e\rightarrow NO_2+H_2O\)

\(n_{NO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

Bảo toàn e: \(n_{Cu}.2=n_{NO_2}.1\)

=> \(n_{Cu}=0,1\left(mol\right)\)

=> \(m_{Cu}=0,1.64=6,4\left(g\right)\)

=>\(m_{Fe,Al}=14,7-6,4=8,3\left(g\right)\)

Ta có : Trong 14,7g hh Fe, Al, Cu thì chứa 8,3 g hh Fe và Al

=> Trong 3,48g hh Fe,Al,Cu  thì chứa 1,96 g hh Fe và Al

\(n_{H_2}=\dfrac{1,792}{22,4}=0,08\left(mol\right)\)

Fe + 2HCl → FeCl2 + H2

2Al + 6HCl → 2AlCl3 + 3H2

Đặt nFe = x ; nAl= y

Ta có: \(\left\{{}\begin{matrix}56x+27y=1,96\\x+\dfrac{3}{2}y=0,08\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=0,014\\y=0,044\end{matrix}\right.\)

=>\(m_{Fe}=0,014.56=0,784\left(g\right)\)

\(m_{Al}=0,044.27=1,188\left(g\right)\)

Ta có : Trong 3,48g hh Fe,Al,Cu  thì chứa 0,78 Fe và 1,188g Al

=> Trong 14,7g hh Fe, Al, Cu thì chứa 3,31 g  Fe và 5,02g Al

(Các số tính gần đúng thôi vì khi tính khối lượng của Fe và Al trong 3,48g đã lẻ rồi nhé bạn )

Em ơi , chụp lại đề đi em !

My school seems big from the outside, but is really quite small once you get to know it. It is full of beautiful red brick buildings with arches and ivory. It also has a few more contemporary buildings thrown in there, one parularly interesting one looks a cheese grater :) I think my campus is gorgeous. There is a lovely green quad outside of the freshman dorms and when you walk across it on a warm and sunny SoCal day, you will be amazed. And just wait till you see campus on Game Day, it is a swarm of gold and maroon you have never seen before. My mom still talks about her first game day and seeing the crowds of the people who came out to support the Trojans.

desrcibe ms đúng nhé

Iam going to discuss about my secondary school namely ...........It is one the famous and good school, which is located in .............. and takes 1kms from my village.I studied in this school up to my 5th standard and the syllabus taught here is central syllabus. I used to get good ranks and teachers are from kerala state and they are majors in distinct fields.I really enjoyed my schooling with my friends by playing different games in play ground, coco is one of the best Indian games, which we used to play almost every day for one hour except weekends.To conclude, the school is well-established that contain all sort of facilities , which os necessary for school.

Cảm ơn bn

VII. Write a thank-you letter using the words given. (10 pts)
Dear Nhung,
1. Thank you/ much/ the flowers/ you/ send/ while/ I/ be/ hospital.
_______Thank you very much for the flowers you sent me while I was in the hospital____________________________________
2. They/beautiful/ and/ they/ really/ help/ cheer/ me/ up.
_____They were very beautiful and they really helped to cheer me up______________________________________
3. I/ come out/ hospital/ last Thursday morning.
____I came out of the hospital last Thursday morning_______________________________________
4. You/ come over/ place/ weekend/ because/ I/ very/ bored/ now?
___Will you come over to my place on the weekend because I am very bored now?________________________________________
5. I/ look forward/see/soon.
_____I am looking forward to seeing you soon______________________________________
Love, (Thao)
VIII. Read the passages the fill in each blank with a suitable word. (10 pts)
How Nam has improved his English.
In the first year of lower secondary (1)___school_____, I had some difficulties
in learning English. My English pronunciation (2)____was___ really bad and my
English grammar was worse. I did not (3)___know____ how to improve them. I didn’t
want my father (4)__and_____ mother to know about this. One afternoon after the
lesson, my teacher (5)____in___ English told me to wait 6)___for____ her outside the
classroom. She took (7)____me___ to the school library and showed me tapes of
pronunciation drills kept in a glass bookcase. She also told me how to use an
English- English dictionary to (8)____improve___ my English grammar. “Now I think you
know what you should do” she said. I made much progress and only one year
later, I won the first (9)____prize___ in the English Speaking Contest (10)____organized___ for

1. The post office is not far_from___ my house.
2. Mrs. Lien said you could reach her__at__ 8 603 312.
3. Snow is falling all__over__ the country.
4. Will you pick me__up__ after the party?
5. We all agreed__with__ their request for a full investigation.

VII 1. Thank you/ much/ the flowers/ you/ send/ while/ I/ be/ hospital.

 Thank you very much for the flowers you sent me while I was in the hospital.

2. They/beautiful/ and/ they/ really/ help/ cheer / me/ up.

 They were very beautiful and they really helped to cheer me up.

3. I/ come out/ hospital/ last Thursday morning.

 I came out of the hospital last Thursday morning.

4. You/ come over/ place/ weekend/ because/ I/ very/ bored/ now?

 Will you come over to my place on the weekend because I am very bored now?

5. I/ look forward/see/soon.

 I am looking forward to seeing you soon.

VIII

1. school

2. was

3. know

4. and

5. of

6. for

7. me

8. improve

9. prize

10. held