1/ Cho phản ứng: H₂SO4 đặc + Al → Al₂(SO4)₃ + H₂S + H₂O. Tổng hệ số cân bằng của H2SO4 đặc và Al là: (Nêu cách tính)

A. 19 B. 28 C. 25 D. 23

2/ Hòa tan 11,2 gam Fe bằng dung dịch H₂SO₄ loãng (dư), thu được dung dịch X. Dung dịch X phản ứng vừa đủ với Vml dung dịch KMnO₄ 0,5M. Giá trị của V là:

A. 40 B. 80 C. 60 D.20

3/ Cho hỗn hợp gồm Fe và FeS tác dụng với dung dịch HCl dư, khí sinh ra có tỷ khối so với hidro là 9. Thành phần % theo khối lượng Fe trong hỗn hợp ban đầu là:

A. 40% B. 38,89% C. 50% D. 61,11%

4/ Một hỗn hợp gồm 13 gam Zn và 5,6 gam Fe tác dụng với dung dịch H₂SO₄ loãng dư. Thể tích khí hidro (đktc) được giải phóng sau phản ứng là:

A. 2,24 lít B. 4,48 lít C. 6,72 lít D. 67,2 lít

1/ Trong mặt phẳng Oxy cho A(1; 2), B(3; -4) và đường thẳng d: 3x - 4y + 5 = 0.

Viết phương trình đường tròn có tâm B và tiếp xúc với đường thẳng d.

2/ Cho elip (E):\(\frac{x^2}{5}+\frac{y^2}{4}=1\).Tìm tỉ số giữa tiêu cự và độ dài trục lớn của (E).

CHỨNG MINH ĐẲNG THỨC

a/ Chứng minh rằng: \(\frac{sin4x-sin2x}{1-cos2x+cos4x}=tanx\)( với x là giá trị để biểu thức có nghĩa)

b/ Cho x ≠ k\(\frac{\pi}{4}\) , kϵ Z . Chứng minh đẳng thức sau:\(\frac{1-cos4x}{sin4x}=tanx\)

Nêu đặc điểm có lợi, có hại của vi sinh vật: nấm men, nấm mốc, tụ cầu khuẩn, trực khuẩn, xạ khuẩn, xoắn khuẩn, vi khuẩn lactobacillus

Write a paragraph about preservation of the environment. The following suggests may be useful for you:

- reduce the use of fossil fuels for energy.

- plant more trees and prevent deforestation.

- use public means of transport.

- raise people's awareness of protecting the environment.

**Change these sentences into Reported Speech:

1/ "There isn't any milk in this bottle, Ann." Mike said

→__________________________________

2/ She said, " You can come with us if you like".

→__________________________________

3/ The old man said, " I will take you to my house right now".

→__________________________________

4/ He was still declaring, " You are the man who did it".

→__________________________________

5/ Mum said to me, " Buy some apples at the groceries".

→__________________________________

6/ " Please remove your shoes before entering, "Linda said to Tony.

→__________________________________

7/ " Write me a letter every week, " Ha said to her friend.

→__________________________________

8/ " Can you lock the door, please?" Tom said to me.

→__________________________________

9/ Austin said to me, " Could you help me with the homework?"

→__________________________________

I. Rewrite the following sentences with the words given

1/. Asian countries should balance the gender equality.

The______________________________

2/. Dangerous driving will cause many serious road accidents.

Many serious______________________

3/. Applicants must return this form by 21^st March.

This form_________________________

4/. We will not accept his apology.

His______________________________

5/. I have never done a more difficult exercise than this before.

This is___________________________

6/. This is the worst tennis player in this club I have ever played with.

I have___________________________

II. Choose the underlined word or phrase that needs correcting

1/. Have you ever read "Oliver Twist", a interesting novel written by Charles Dickens ?

A. ever read B. a interesting novel C. written D.by

2/. Please send me the smallest, most recently published, and less expensive dictionary that you have available.

A. me B. the C. recently D. less

3/. The man tells me that this room can use after 10 o'clock.

A. the B. tells me C. that this D. use

III. Choose the sentence that is closest in meaning to each of the following questions

1/. The environment in the region isn't as clean as it used to be

A. The environment in the region is cleaner than it used to be

B. The environment in the region used to be cleaner than it is now

C. The environment in the region used to be polluted than it is now

D. The environment now is the cleanest in the region

2/. This is the most delicious cake I've ever tasted

A. The last time I ate such a delicious cake

B. I've never tasted a more delicious cake than this one

C. This cake is more delicious than that one

D. The cake is so delicious that I ate a lot

3/. I can't run as fast as I used to

A. I used to run more slowly than I can now

B. I used to run as quickly as I can now

C. I used ro run faster than I can now

D. I always ran as fast as I can now

4/. There are more sports competed in this SEA Games than in last SEA Games

A. The sports competed ill this SEA Games are the same as those in last SEA Games

B. Not as many sports were competed in last SEA Games as in this SEA Games

C. In the last SEA Games there were some sports which were not compete

D. In this SEA Games, there are less sports competed than in last SEA Games

5/. The test we did last time was more difficult than this one

A. We did an easy test last time and a difficult one this one

B. This test is not as difficult as the one we did last time

C. This time we have to do the most difficult test of all

D. The test we have done this time is not difficult at all