Cho đường tròn (O) có 2 đường kính AB và CD vuông góc với nhau. Gọi M là một điểm trên cung nhỏ BC (M khác B,C) và I là giao điểm của AM với CD
a) Chứng minh tứ giác OIMB nội tiếp đường tròn 
b) Chứng minh hai tam giác AIC và ACM đồng dạng
c) Gọi K là điểm đối xứng của I qua BC. Chứng minh ba điểm B, M, K thẳng hàng.
 Mọi người làm giúp em câu c thôi ạ!

I. Read the passage and decide whether the statements are True or False
Electricity is the most common form of energy today. In the modern world, electricity is very available at the touch of a switch. Electricity has many uses. The most common use of electricity is to provide artificial lighting. In factories, electricity is used to light up the workplace. It is also used to operate air-conditioners, computers and many other machines. Electricity is also used to power the many appliances that we have in our homes. Such appliances include television sets, computers,
electric fans, irons, and many others. The list is simply endless. Modern man will most probably be lost without electricity.
 

Part II: Read and choose the best answers.
Tropical rain forests are found in the Amazon region of South America, Central America, Africa, South, and Southeast Asia. Rain forests are very important to the world’s climate. The Amazon rain forests alone receive about 30 to 40 percent of the total rainfall on the earth and produce about the same percentage of the world’s oxygen. Some scientists believe that the decrease of rain forests will affect the climate on the earth, making it uncomfortable or even dangerous for life. Saving our rainforests is an international problem. One country or even a few countries cannot solve the problem alone. The nations of the world must work together to find a solution before it is too late.
1. Rain forests are ______ to the world’s climate.
A. significant      B. dangerous     C. unnecessary      D. international
2 The Amazon rain forests receive ______ of the total rainfall on the earth.
A. 20% - 30%     B. 30% - 40%      C. 40% - 50%     D. 50% - 60%
3. Some scientists believe that the decrease of rain forests will _____ the climate on the earth.
A. not influence       B. change    C. keep        D. remain
4. The decrease of rain forests will make people’s life______.
A. comfortable B. unpleasant C. easy D. smooth
5. Saving rain forests is a ______ problem.
A. national B. local C. global D. provincial
6. The nations of the world must ______ to protect rain forests.
A. work hard B. incorporate C. work well D. cooperate

đốt cháy hoàn toàn 1.12(l) etylen trong không khí 
a) Tính V không khí cần dùng (đktc)
b) Dẫn lượng etylen trên đi qua dd Brom. Tính khối lượng Brom bị mất màu

nêu ví dụ một số rừng ngập mặn ở vùng Đồng bằng sông Cửu Long

cho mình xin đề kiểm tra 15' unit 6: The Environment với

Complete each sentence of the following letter.

Dear Mr. Smith,

1.      I write/ complain/ dirt/ smoke/ come/ your factory chimneys.

............................................................................................................................

2.      Two days ago/ I decide/ do / my washing.

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3.      I wash/ sheets/ put/ out/ dry/ it/ be/ nice sunny day/ there/ be/ breeze.

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4.      When I take washing in/ I be/ horrified/ discovered/ it/ cover/ dirty marks.

_{.....................................................................................................................................................}

5.      I/ assume/ breeze/ I/ mention/ carry/ dirt/ chimneys.

_{.....................................................................................................................................................}

6.      This be/ not only/ because/ sheets/ but because/ we/ two small children/ who be make/ breathe/ same air.

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7.      Until this incident/ I think/ chimneys/ be safe/ clean.

_{.......................................................................................................................................}

8.      I already/ write/ local Member of Parliament/ this matter.

_{.....................................................................................................................................................}

9.      Furthermore/ I must warn you/ I/ write/ local newspaper/ tomorrow.

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10.  I/ look forward/ receive/ reply.

_{.....................................................................................................................................................}

Yours sincerely

Mrs. Jennifer Hunter

giải thích hiện tượng xảy ra khi nhiệt phân muối NaHCO₃ bằng lời.