Cho góc xoy < 90 độ, trên nửa mặt phẳng bờ oy chứa ox, vẽ tia oz ⊥ oy. Trên nửa mặt phẳng bờ ox vẽ tia ot⊥ ox. Lấy A∈ ox, B∈ oy, C ∈oz, D ∈ot sao cho OA=OB,OC=OD

 AD cắt BC tại E. c/m OE vuông goc với AB

Cho tam giác ABC cân tại A (^A < 90 độ). Kẻ BD vuông góc AC (D thuộc AC), CE vuông góc AB (E thuộc AB), BD và CE cắt nhau tại H.

a) Chứng minh BD = CE

b) Chứng minh tam giác HBC cân

c) Chứng minh AH là phân giác của góc A

d) Trên tia BD lấy điểm K sao cho D là trung điểm của BK. So sánh góc ECB và góc DKC

Cho góc xoy < 90 độ, trên nửa mặt phẳng bờ oy chứa ox, vẽ tia oz ⊥ oy. Trên nửa mặt phẳng bờ ox vẽ tia ot⊥ ox. Lấy A∈ ox, B∈ oy, C ∈oz, D ∈ot sao cho OA=OB,OC=OD

a) So sánh AC với BD

b) AD cắt BC tai E. c/m OE ⊥ AB

II. Choose the word or phrase that best completes each unfinished sentence below or substitutes for the underlined word or phrase. 

Các bạn giúp mình ghi lí do chọn đáp án này với ạ! Cảm ơn nhiều 

6. It seems you often_........ up very early.

a. get                   b. got   c. getting                     d. getted
7. Water _____ at 100°C.

a. boil        b. boils            c. boiled                      d. is boiling
8. In the kitchen, there was a _______ table.

a. beautiful large wooden round         b. beautiful large round wooden     

c. large wooden beautiful round            d. round wooden beautiful large
9. He wasn’t ______ the job.

a. experienced enough to                  b. enough experienced to
c. experienced enough for                   d. enough experienced for
10. Is there enough room _____ in the car?

a. for me           b. to me           c. for I             d. to I
11. That was one of the _____ days of my life.

a. gladdest   b. most glad    c. happiest                  d. most happy
12. Jane wants to go to the cinema but I would prefer ___at home.

a. stay   b. to stay c. to staying            d. for staying
13. I live ______20 Oxford Street.

a. in         b. at                 c. on                d. from
14. It was generous _______ you to share your food with me.

a. of b. to     c. for                d. about
15. I was late, but ________ they waited for me.

a. lovely    b. luckily        c. extremely    d. silly 

Tiến hóa về sinh sản được thể hiện như thế nào?

 Cho ΔABC cân tại A, đường cao AH. Biết AB = √97 cm, BC = 8cm.

a) Tính độ dài các đoạn thẳng BH, AH.

b) Gọi K là trung điểm của AC, tính độ dài BK

Tìm lỗi sai và sửa lại

1.I’ve come  up  in  an idea  about  our  environmental  project.

2.If urban citizens take better care of the environment, the city would not be so dirty.

3. She showed me where did I left my luggage.                                    

4. He had not idea how difficult the job was.

5. It was late, so we decided taking a taxi home.       

119. Why/ river water/ heavy/ contaminate? =à =>__________________________________________________________________________

120. Most teenagers/ would rather/ chat/ friends/ online/ see/ them/ in person.

=>__________________________________________________________________________

C. Finish the second sentence so that it has a similar meaning to the first one, beginning with the given words.

111. They told me, “We are having a workshop on new building materials this weekend”.

 They ______________________________________________________________________

112. I can’t come to your party because I have to help my brother with his homework.

 If _________________________________________________________________________

113. The last time we came back to our hometown was six years ago.

We haven’t _________________________________________________________________

114. “Who did you see at the meeting?”, my mother asked. 

My mother ___________________________

115. A few well-chosen words convey a great deal of meaning.

A great ______________________